Suppress GCC's false -Warray-bounds error in set_parents() with JSON_DIAGNOSTICS

With JSON_DIAGNOSTICS, GCC 13 to 15 report a false -Warray-bounds error
at -O3 when set_parents() is inlined right after a non-container value
(e.g., a string) was created: the std::map access in the object branch
is checked against the string allocation although m_type rules that
branch out. GCC 15 fixed the pattern from #4819 but not this one.

Suppress -Warray-bounds around set_parents() only, and add a regression
test that is compiled with -O3 -Werror=array-bounds on GCC.

Fixes #5742

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

docs/mkdocs/docs/api/basic_json/dump.md

@@ -25,12 +25,10 @@ and `ensure_ascii` parameters.
     result consists of ASCII characters only.
 
 `error_handler` (in)
-:   how to react on decoding errors; there are four possible values (see [`error_handler_t`](error_handler_t.md):
+:   how to react on decoding errors; there are three possible values (see [`error_handler_t`](error_handler_t.md):
     `strict` (throws an exception in case a decoding error occurs; default), `replace` (replace invalid UTF-8 sequences
-    with U+FFFD), `ignore` (ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the
+    with U+FFFD), and `ignore` (ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the
-    output unchanged, and invalid bytes are dropped), and `keep` (write the ill-formed bytes to the output as is,
+    output unchanged, and invalid bytes are dropped)).
-    without escaping them, even if `ensure_ascii` is `#!cpp true`; the result is then not valid UTF-8, but equals the
-    input bytes exactly, and well-formed characters around the ill-formed bytes are still escaped as usual)).
     
 ## Return value
 
@@ -96,4 +94,3 @@ Binary values are serialized as an object containing two keys:
 - Indentation character `indent_char`, option `ensure_ascii` and exceptions added in version 3.0.0.
 - Error handlers added in version 3.4.0.
 - Serialization of binary values added in version 3.8.0.
-- Error handler `keep` added in version 3.13.0.

docs/mkdocs/docs/api/basic_json/error_handler_t.md

@@ -4,30 +4,15 @@
 enum class error_handler_t {
     strict,
     replace,
-    ignore,
+    ignore
-    keep
 };
 ```
 
-This enumeration is used to choose how to treat ill-formed UTF-8 in a string value or object key:
+This enumeration is used in the [`dump`](dump.md) function to choose how to treat decoding errors while serializing a
-
+`basic_json` value. Three values are differentiated:
-- [`dump`](dump.md) uses it while serializing a `basic_json` value to text.
-- [`to_cbor`](to_cbor.md), [`to_ubjson`](to_ubjson.md), [`to_bjdata`](to_bjdata.md), and [`to_bson`](to_bson.md) use it
-  while serializing a `basic_json` value to that binary format; none of CBOR, UBJSON, BJData, or BSON requires a
-  decoder to reject ill-formed UTF-8, so by default (`strict`) the library checks on write instead. `to_msgpack` and
-  `to_bon8` do not take this parameter: MessagePack's specification explicitly allows a string to contain ill-formed
-  UTF-8, so `to_msgpack` always passes it through, while BON8 always validates, since UTF-8 lead bytes are structural
-  to that format.
-- [`from_cbor`](from_cbor.md), [`from_msgpack`](from_msgpack.md), [`from_ubjson`](from_ubjson.md),
-  [`from_bjdata`](from_bjdata.md), and [`from_bson`](from_bson.md) use it while parsing that binary format, to decide
-  whether to check a string value or object key for well-formed UTF-8 at all; by default (`keep`) they do not, as no
-  binary reader did before this parameter was added. `from_bon8` does not take this parameter, for the same reason
-  `to_bon8` does not.
-
-Four values are differentiated:
 
 strict
-:   throw a `type_error`/`parse_error` exception in case of invalid UTF-8
+:   throw a `type_error` exception in case of invalid UTF-8
 
 replace
 :   replace invalid UTF-8 sequences with U+FFFD (� REPLACEMENT CHARACTER)
@@ -35,12 +20,6 @@ replace
 ignore
 :   ignore invalid UTF-8 sequences; all valid bytes are copied to the output unchanged, and invalid bytes are dropped
 
-keep
-:   keep invalid UTF-8 sequences unchanged; only meaningful for the binary formats mentioned above, since [`dump`]
-    (dump.md) itself must produce text, and `keep` there writes the ill-formed bytes to the output as is, so the
-    result is then not valid UTF-8 (but still equals the input bytes exactly, including around any well-formed
-    characters, which are still escaped as usual)
-
 ## Examples
 
 ??? example
@@ -61,5 +40,3 @@ keep
 ## Version history
 
 - Added in version 3.4.0.
-- Added `keep`, and made this enumeration apply to the binary readers and writers in addition to `dump`, in version
-  3.13.0.

docs/mkdocs/docs/api/basic_json/from_bjdata.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_bjdata(InputType&& i,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
+                              const bool allow_exceptions = true);
-                              const error_handler_t error_handler = error_handler_t::keep);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_bjdata(IteratorType first, SentinelType last,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
+                              const bool allow_exceptions = true);
-                              const error_handler_t error_handler = error_handler_t::keep);
 ```
 
 Deserializes a given input to a JSON value using the BJData (Binary JData) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    BJData does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,7 +73,7 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if a parse error occurs
 - Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string could not be parsed
-  successfully, or if a string value or object key is not valid UTF-8 and `error_handler` is `strict`
+  successfully
 - Throws [out_of_range.408](../../home/exceptions.md#jsonexceptionout_of_range408) if the size of an optimized container
   or n-dimensional array cannot be represented by `std::size_t`
 
@@ -119,4 +111,3 @@ Linear in the size of the input.
 - Added in version 3.11.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/from_bson.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_bson(InputType&& i,
                             const bool strict = true,
-                            const bool allow_exceptions = true,
+                            const bool allow_exceptions = true);
-                            const error_handler_t error_handler = error_handler_t::keep);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_bson(IteratorType first, SentinelType last,
                             const bool strict = true,
-                            const bool allow_exceptions = true,
+                            const bool allow_exceptions = true);
-                            const error_handler_t error_handler = error_handler_t::keep);
 ```
 
 Deserializes a given input to a JSON value using the BSON (Binary JSON) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    BSON does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -83,8 +75,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   invalid string or byte array length)
 - Throws [`parse_error.114`](../../home/exceptions.md#jsonexceptionparse_error114) if an unsupported BSON record type is
   encountered
-- Throws [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) if a string value or object key is
-  not valid UTF-8 and `error_handler` is `strict`
 
 ## Complexity
 
@@ -121,7 +111,6 @@ Linear in the size of the input.
 - Added in version 3.4.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_cbor.md

@@ -6,16 +6,14 @@ template<typename InputType>
 static basic_json from_cbor(InputType&& i,
                             const bool strict = true,
                             const bool allow_exceptions = true,
-                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
+                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error);
-                            const error_handler_t error_handler = error_handler_t::keep);
 
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_cbor(IteratorType first, SentinelType last,
                             const bool strict = true,
                             const bool allow_exceptions = true,
-                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
+                            const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error);
-                            const error_handler_t error_handler = error_handler_t::keep);
 ```
 
 Deserializes a given input to a JSON value using the CBOR (Concise Binary Object Representation) serialization format.
@@ -67,12 +65,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   how to treat CBOR tags (optional, `error` by default); see [`cbor_tag_handler_t`](cbor_tag_handler_t.md) for more
     information
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    CBOR does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -88,9 +80,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from CBOR were
   used in the given input or if the input is not valid CBOR
-- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of
+- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
-  other types are not supported, as JSON object keys are always strings), or if a string value or object key is not
+  types are not supported, as JSON object keys are always strings) or a string is malformed
-  valid UTF-8 and `error_handler` is `strict`
 
 ## Complexity
 
@@ -130,7 +121,6 @@ Linear in the size of the input.
 - Added `tag_handler` parameter in version 3.9.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_msgpack.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_msgpack(InputType&& i,
                                const bool strict = true,
-                               const bool allow_exceptions = true,
+                               const bool allow_exceptions = true);
-                               const error_handler_t error_handler = error_handler_t::keep);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_msgpack(IteratorType first, SentinelType last,
                                const bool strict = true,
-                               const bool allow_exceptions = true,
+                               const bool allow_exceptions = true);
-                               const error_handler_t error_handler = error_handler_t::keep);
 ```
 
 Deserializes a given input to a JSON value using the MessagePack serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    MessagePack's specification explicitly allows ill-formed UTF-8, so checking is opt-in: the default, `keep`, does
-    not check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,9 +73,8 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if unsupported features from
   MessagePack were used in the given input or if the input is not valid MessagePack
-- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of
+- Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a map key is not a string (keys of other
-  other types are not supported, as JSON object keys are always strings), or if a string value or object key is not
+  types are not supported, as JSON object keys are always strings) or a string is malformed
-  valid UTF-8 and `error_handler` is `strict`
 
 ## Complexity
 
@@ -122,7 +113,6 @@ Linear in the size of the input.
 - Added `allow_exceptions` parameter in version 3.2.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/from_ubjson.md

@@ -5,14 +5,12 @@
 template<typename InputType>
 static basic_json from_ubjson(InputType&& i,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
+                              const bool allow_exceptions = true);
-                              const error_handler_t error_handler = error_handler_t::keep);
 // (2)
 template<typename IteratorType, typename SentinelType = IteratorType>
 static basic_json from_ubjson(IteratorType first, SentinelType last,
                               const bool strict = true,
-                              const bool allow_exceptions = true,
+                              const bool allow_exceptions = true);
-                              const error_handler_t error_handler = error_handler_t::keep);
 ```
 
 Deserializes a given input to a JSON value using the UBJSON (Universal Binary JSON) serialization format.
@@ -60,12 +58,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `allow_exceptions` (in)
 :   whether to throw exceptions in case of a parse error (optional, `#!cpp true` by default)
 
-`error_handler` (in)
-:   how to treat a string value or object key that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    UBJSON does not require a decoder to reject ill-formed UTF-8, so checking is opt-in: the default, `keep`, does not
-    check at all, as every binary reader did before this parameter was added; `strict` checks and throws;
-    `replace`/`ignore` sanitize the string the same way [`dump`](dump.md) would
-
 ## Return value
 
 deserialized JSON value; in case of a parse error and `allow_exceptions` set to `#!cpp false`, the return value will be
@@ -81,7 +73,7 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
   the end of the file was not reached when `strict` was set to true
 - Throws [parse_error.112](../../home/exceptions.md#jsonexceptionparse_error112) if a parse error occurs
 - Throws [parse_error.113](../../home/exceptions.md#jsonexceptionparse_error113) if a string could not be parsed
-  successfully, or if a string value or object key is not valid UTF-8 and `error_handler` is `strict`
+  successfully
 - Throws [out_of_range.408](../../home/exceptions.md#jsonexceptionout_of_range408) if the size of an optimized container
   or n-dimensional array cannot be represented by `std::size_t`
 
@@ -120,7 +112,6 @@ Linear in the size of the input.
 - Added `allow_exceptions` parameter in version 3.2.0.
 - Extended container support (1) to include types with lvalue-only ADL `begin`/`end` (matching `std::begin`/`std::end` semantics) in version 3.13.0.
 - Extended overload (2) to accept heterogeneous iterator+sentinel pairs (C++20 ranges support) in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.
 
 !!! warning "Deprecation"
 

docs/mkdocs/docs/api/basic_json/to_bjdata.md

@@ -5,18 +5,15 @@
 static std::vector<std::uint8_t> to_bjdata(const basic_json& j,
                                            const bool use_size = false,
                                            const bool use_type = false,
-                                           const bjdata_version_t version = bjdata_version_t::draft2,
+                                           const bjdata_version_t version = bjdata_version_t::draft2);
-                                           const error_handler_t error_handler = error_handler_t::strict);
 
 // (2)
 static void to_bjdata(const basic_json& j, detail::output_adapter<std::uint8_t> o,
                       const bool use_size = false, const bool use_type = false,
-                      const bjdata_version_t version = bjdata_version_t::draft2,
+                      const bjdata_version_t version = bjdata_version_t::draft2);
-                      const error_handler_t error_handler = error_handler_t::strict);
 static void to_bjdata(const basic_json& j, detail::output_adapter<char> o,
                       const bool use_size = false, const bool use_type = false,
-                      const bjdata_version_t version = bjdata_version_t::draft2,
+                      const bjdata_version_t version = bjdata_version_t::draft2);
-                      const error_handler_t error_handler = error_handler_t::strict);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the BJData (Binary JData) serialization format. BJData aims to
@@ -46,12 +43,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   which version of BJData to use (see note on "Binary values" on [BJData](../../features/binary_formats/bjdata.md));
 optional, `#!cpp bjdata_version_t::draft2` by default.
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_bjdata` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. BJData serialization as byte vector
@@ -65,8 +56,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 
 - Throws [`other_error.502`](../../home/exceptions.md#jsonexceptionother_error502) if `use_type` is true and `use_size`
   is false.
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -101,5 +90,3 @@ Linear in the size of the JSON value `j`.
 
 - Added in version 3.11.0.
 - BJData version parameter (for draft3 binary encoding) added in version 3.12.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_bson.md

@@ -2,14 +2,11 @@
 
 ```cpp
 // (1)
-static std::vector<std::uint8_t> to_bson(const basic_json& j,
+static std::vector<std::uint8_t> to_bson(const basic_json& j);
-                                         const error_handler_t error_handler = error_handler_t::strict);
 
 // (2)
-static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
+static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o);
-                    const error_handler_t error_handler = error_handler_t::strict);
+static void to_bson(const basic_json& j, detail::output_adapter<char> o);
-static void to_bson(const basic_json& j, detail::output_adapter<char> o,
-                    const error_handler_t error_handler = error_handler_t::strict);
 ```
 
 BSON (Binary JSON) is a binary format in which zero or more ordered key/value pairs are stored as a single entity (a
@@ -28,12 +25,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `o` (in)
 :   output adapter to write serialization to
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_bson` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. BSON serialization as a byte vector
@@ -55,8 +46,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 - Throws [`out_of_range.415`](../../home/exceptions.md#jsonexceptionout_of_range415) if the subtype of a binary value
   exceeds 255, the maximum of the BSON binary subtype; example:
   `"subtype 70000 is too large for the BSON binary subtype (max 255)"`
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -93,6 +82,3 @@ pass before anything is written.
 - Added in version 3.4.0.
 - Linear in the size of `j`, and no longer limited by the call stack for deeply nested values, since version 3.13.0.
 - `out_of_range.415` is now detected before anything is written, like the other exceptions above, since version 3.13.0.
-- Throwing `type_error.316` for a string value or object key that is not valid UTF-8, detected before anything is
-  written, added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_cbor.md

@@ -2,14 +2,11 @@
 
 ```cpp
 // (1)
-static std::vector<std::uint8_t> to_cbor(const basic_json& j,
+static std::vector<std::uint8_t> to_cbor(const basic_json& j);
-                                          const error_handler_t error_handler = error_handler_t::strict);
 
 // (2)
-static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o,
+static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o);
-                     const error_handler_t error_handler = error_handler_t::strict);
+static void to_cbor(const basic_json& j, detail::output_adapter<char> o);
-static void to_cbor(const basic_json& j, detail::output_adapter<char> o,
-                     const error_handler_t error_handler = error_handler_t::strict);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the CBOR (Concise Binary Object Representation) serialization
@@ -29,12 +26,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 `o` (in)
 :   output adapter to write serialization to
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_cbor` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. CBOR serialization as a byte vector
@@ -44,11 +35,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 
 Strong guarantee: if an exception is thrown, there are no changes in the JSON value.
 
-## Exceptions
-
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
-
 ## Complexity
 
 Linear in the size of the JSON value `j`.
@@ -82,5 +68,3 @@ Linear in the size of the JSON value `j`.
 
 - Added in version 2.0.9.
 - Compact representation of floating-point numbers added in version 3.8.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_ubjson.md

@@ -4,16 +4,13 @@
 // (1)
 static std::vector<std::uint8_t> to_ubjson(const basic_json& j,
                                            const bool use_size = false,
-                                           const bool use_type = false,
+                                           const bool use_type = false);
-                                           const error_handler_t error_handler = error_handler_t::strict);
 
 // (2)
 static void to_ubjson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
-                      const bool use_size = false, const bool use_type = false,
+                      const bool use_size = false, const bool use_type = false);
-                      const error_handler_t error_handler = error_handler_t::strict);
 static void to_ubjson(const basic_json& j, detail::output_adapter<char> o,
-                      const bool use_size = false, const bool use_type = false,
+                      const bool use_size = false, const bool use_type = false);
-                      const error_handler_t error_handler = error_handler_t::strict);
 ```
 
 Serializes a given JSON value `j` to a byte vector using the UBJSON (Universal Binary JSON) serialization format. UBJSON
@@ -39,12 +36,6 @@ The exact mapping and its limitations are described on a [dedicated page](../../
 :   whether to add type annotations to container types (must be combined with `#!cpp use_size = true`); optional,
     `#!cpp false` by default.
 
-`error_handler` (in)
-:   how to treat a string or object key in `j` that is not valid UTF-8; see [`error_handler_t`](error_handler_t.md).
-    The default, `strict`, throws; `keep` writes the ill-formed bytes to the output as is, as every version of
-    `to_ubjson` did before this parameter was added; `replace`/`ignore` sanitize it the same way
-    [`dump`](dump.md) would
-
 ## Return value
 
 1. UBJSON serialization as a byte vector
@@ -58,8 +49,6 @@ Strong guarantee: if an exception is thrown, there are no changes in the JSON va
 
 - Throws [`other_error.502`](../../home/exceptions.md#jsonexceptionother_error502) if `use_type` is true and `use_size`
   is false.
-- Throws [type_error.316](../../home/exceptions.md#jsonexceptiontype_error316) if a string or object key in `j` is
-  not valid UTF-8 and `error_handler` is `strict` (the default)
 
 ## Complexity
 
@@ -93,5 +82,3 @@ Linear in the size of the JSON value `j`.
 ## Version history
 
 - Added in version 3.1.0.
-- Throwing `type_error.316` for a string or object key that is not valid UTF-8 added in version 3.13.0.
-- Added `error_handler` parameter in version 3.13.0.

docs/mkdocs/docs/examples/error_handler_t.cpp

@@ -20,6 +20,5 @@ int main()
               << j_invalid.dump(-1, ' ', false, json::error_handler_t::replace)
               << "\nstring with ignored invalid characters: "
               << j_invalid.dump(-1, ' ', false, json::error_handler_t::ignore)
-              << "\nstring with the invalid byte kept as is (" << j_invalid.dump(-1, ' ', false, json::error_handler_t::keep).size()
+              << '\n';
-              << " bytes, not valid UTF-8 itself)\n";
 }

docs/mkdocs/docs/examples/error_handler_t.output

@@ -1,4 +1,3 @@
 [json.exception.type_error.316] invalid UTF-8 byte at index 2: 0xA9
 string with replaced invalid characters: "ä�ü"
 string with ignored invalid characters: "äü"
-string with the invalid byte kept as is (7 bytes, not valid UTF-8 itself)

docs/mkdocs/docs/features/binary_formats/bjdata.md

@@ -63,12 +63,6 @@ The library uses the following mapping from JSON values types to BJData types ac
 
       - strings with more than 18446744073709551615 bytes, i.e., 2<sup>64</sup>-1 bytes (theoretical)
 
-!!! warning "UTF-8 validation of string values and object keys"
-
-    BJData strings must use UTF-8 encoding. `to_bjdata()` validates the bytes of every string value and object key
-    and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for ill-formed UTF-8, so a
-    value with such a string cannot be serialized in the first place.
-
 !!! info "Unused BJData markers"
 
     The following markers are not used in the conversion:
@@ -214,20 +208,6 @@ The library maps BJData types to JSON value types as follows:
 
     The mapping is **complete** in the sense that any BJData value can be converted to a JSON value.
 
-!!! warning "Ill-formed UTF-8 in string values and object keys"
-
-    BJData strings must use UTF-8 encoding, but checking it on read is opt-in: with the
-    [`error_handler`](../../api/basic_json/from_bjdata.md) parameter left at `keep` (the default), `from_bjdata()`
-    accepts a string value or object key whose bytes are not valid UTF-8 and hands them back unchanged. Passing
-    `error_handler_t::strict` makes `from_bjdata()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read with the default
-    `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes. `to_bjdata()`'s
-    own `error_handler` parameter defaults to `strict` (see above), so a value read this way cannot be written back
-    to BJData unless a non-strict handler is passed there too.
-
 !!! info "Round trips"
 
     A value returned by [`from_bjdata`](../../api/basic_json/from_bjdata.md) can be serialized with

docs/mkdocs/docs/features/binary_formats/bson.md

@@ -109,22 +109,14 @@ The library maps BSON record types to JSON value types as follows:
     If BSON input must be validated for strict specification compliance, validate it separately before passing it to
     `from_bson()`.
 
-!!! warning "Ill-formed UTF-8 in string values"
+!!! warning "UTF-8 validation of string values"
 
-    The BSON specification requires `string` values (type `0x02`) to be valid UTF-8, but this is not required of a
+    The BSON specification requires `string` values (type `0x02`) to be valid UTF-8. This library validates the
-    decoder, so checking is opt-in: with the [`error_handler`](../../api/basic_json/from_bson.md) parameter left at
+    bytes of every such string at decode time and rejects ill-formed UTF-8 with a
-    `keep` (the default), `from_bson()` accepts a `string` value whose bytes are not valid UTF-8 and hands them back
+    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with `allow_exceptions`
-    unchanged. Passing `error_handler_t::strict` makes `from_bson()` check and throw
+    set to `false`, a discarded value), rather than only failing later when the resulting value is dumped. Element
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
+    (key) names and `binary` values (type `0x05`) are unaffected and are never validated, since they are read
-    `replace`/`ignore` sanitize the string instead of keeping it. However, [`dump()`](../../api/basic_json/dump.md)
+    byte-by-byte as a C string, or are not required to hold text, respectively.
-    still requires valid UTF-8 and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)
-    for a value read with the default `keep` handler, unless an error handler is passed that replaces or ignores
-    the ill-formed bytes. `to_bson()`'s own `error_handler` parameter defaults to `strict` and throws the same
-    exception for a string value or element (key) name that is not valid UTF-8, so an object with such a key or
-    value cannot be produced in the first place unless a non-strict handler is passed there, even though
-    `from_bson()` would accept it from another source with the default `keep` handler. Element (key) names are
-    never validated on read, since they are read byte-by-byte as a C string. `binary` values (type `0x05`) are
-    unaffected, since they are not required to hold text.
 
 ??? example
 

docs/mkdocs/docs/features/binary_formats/cbor.md

@@ -189,21 +189,15 @@ The library maps CBOR types to JSON value types as follows:
     ([RFC 8392](https://www.rfc-editor.org/rfc/rfc8392.html)), cannot be read with this library and need a
     general-purpose CBOR library instead.
 
-!!! warning "Ill-formed UTF-8 in text strings"
+!!! warning "UTF-8 validation of text strings"
 
     [RFC 8949, Section 3.1](https://www.rfc-editor.org/rfc/rfc8949.html#section-3.1) requires CBOR text strings
-    (major type 3) to be valid UTF-8, but leaves it up to the decoder whether to enforce this, so checking is
+    (major type 3) to be valid UTF-8. This library validates the bytes of every text string (object keys included) at
-    opt-in: with the [`error_handler`](../../api/basic_json/from_cbor.md) parameter left at `keep` (the default),
+    decode time and rejects ill-formed UTF-8 with a
-    `from_cbor()` accepts a text string (object keys included) whose bytes are not valid UTF-8 and hands them back
+    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with
-    unchanged. Passing `error_handler_t::strict` makes `from_cbor()` check and throw
+    `allow_exceptions` set to `false`, a discarded value), rather than only failing later when the resulting value is
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
+    dumped. Byte strings (major type 2) are unaffected and are never validated, since they are not required to hold
-    `replace`/`ignore` sanitize the string instead of keeping it. However, [`dump()`](../../api/basic_json/dump.md)
+    text.
-    still requires valid UTF-8 and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316)
-    for a value read with the default `keep` handler, unless an error handler is passed that replaces or ignores
-    the ill-formed bytes. `to_cbor()`'s own [`error_handler`](../../api/basic_json/to_cbor.md) parameter defaults
-    to `strict` and throws the same exception for a string value or object key that is not valid UTF-8, so such a
-    value cannot be written back to CBOR unless a non-strict handler is passed there too. Byte strings (major
-    type 2) are unaffected, since they are not required to hold text.
 
 !!! warning "Tagged items"
 

docs/mkdocs/docs/features/binary_formats/messagepack.md

@@ -153,21 +153,14 @@ The library maps MessagePack types to JSON value types as follows:
     This applies to the [SAX interface](../parsing/sax_interface.md) as well, as the key is read before it is passed
     on. Such input needs a general-purpose MessagePack library instead.
 
-!!! warning "Ill-formed UTF-8 in string values"
+!!! warning "UTF-8 validation of string values"
 
-    The MessagePack specification explicitly allows a `str` value (`fixstr`, `str 8`, `str 16`, `str 32`) to contain
+    The MessagePack specification requires `str` values (`fixstr`, `str 8`, `str 16`, `str 32`) to be valid UTF-8.
-    a byte sequence that is not valid UTF-8, and expects a deserializer to hand the original bytes back unchanged.
+    This library validates the bytes of every such string (object keys included) at decode time and rejects
-    This library follows that by default: with its
+    ill-formed UTF-8 with a [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or,
-    [`error_handler`](../../api/basic_json/from_msgpack.md) parameter left at `keep` (the default),
+    with `allow_exceptions` set to `false`, a discarded value), rather than only failing later when the resulting
-    `from_msgpack()` reads `str` bytes (object keys included) as-is, without validating them, so such a value
+    value is dumped. `bin`/`ext`/`fixext` values are unaffected and are never validated, since they are not required
-    round-trips through `from_msgpack(to_msgpack(j))` byte for byte. Passing `error_handler_t::strict` makes
+    to hold text.
-    `from_msgpack()` check anyway and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. `to_msgpack()` itself has no `error_handler`
-    parameter and always writes `str` bytes as-is, since the specification permits it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read this way with the
-    default `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes.
 
 ??? example
 

docs/mkdocs/docs/features/binary_formats/ubjson.md

@@ -47,12 +47,6 @@ The library uses the following mapping from JSON values types to UBJSON types ac
 
       - strings with more than 9223372036854775807 bytes (theoretical)
 
-!!! warning "UTF-8 validation of string values and object keys"
-
-    UBJSON's required string encoding is UTF-8. `to_ubjson()` validates the bytes of every string value and object
-    key and throws [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for ill-formed UTF-8, so
-    a value with such a string cannot be serialized in the first place.
-
 !!! info "Unused UBJSON markers"
 
     The following markers are not used in the conversion:
@@ -126,20 +120,6 @@ The library maps UBJSON types to JSON value types as follows:
 
     The mapping is **complete** in the sense that any UBJSON value can be converted to a JSON value.
 
-!!! warning "Ill-formed UTF-8 in string values and object keys"
-
-    UBJSON's required string encoding is UTF-8, but checking it on read is opt-in: with the
-    [`error_handler`](../../api/basic_json/from_ubjson.md) parameter left at `keep` (the default), `from_ubjson()`
-    accepts a string value or object key whose bytes are not valid UTF-8 and hands them back unchanged. Passing
-    `error_handler_t::strict` makes `from_ubjson()` check and throw
-    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) for ill-formed UTF-8, and
-    `replace`/`ignore` sanitize the string instead of keeping it. However,
-    [`dump()`](../../api/basic_json/dump.md) still requires valid UTF-8 and throws
-    [`type_error.316`](../../home/exceptions.md#jsonexceptiontype_error316) for a value read with the default
-    `keep` handler, unless an error handler is passed that replaces or ignores the ill-formed bytes. `to_ubjson()`'s
-    own `error_handler` parameter defaults to `strict` (see above), so a value read this way cannot be written back
-    to UBJSON unless a non-strict handler is passed there too.
-
 ??? example
 
     ```cpp

docs/mkdocs/docs/home/exceptions.md

@@ -341,10 +341,7 @@ An unexpected byte was read in a [binary format](../features/binary_formats/inde
 
 A string could not be read from a [binary format](../features/binary_formats/index.md): either a value that is not a
 string was read where one was required (for instance as a map key), the string's length specification is invalid, or
-the string's bytes are not valid UTF-8 and the `error_handler` parameter of the corresponding `from_*` function is
+the string's bytes are not valid UTF-8.
-set to `strict`. By default (`error_handler_t::keep`), the bytes of a string are not checked for valid UTF-8 on read;
-see the ill-formed UTF-8 notes on the individual [binary format](../features/binary_formats/index.md) pages for how
-such a string is handled depending on `error_handler`.
 
 CBOR and MessagePack allow map keys of any type, but JSON object keys are always strings. Maps with keys of any other
 type (for instance integers or `null`) are therefore not supported; see the notes on

include/nlohmann/detail/input/binary_reader.hpp

@@ -31,7 +31,6 @@
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/is_sax.hpp>
 #include <nlohmann/detail/meta/type_traits.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
 #include <nlohmann/detail/string_concat.hpp>
 #include <nlohmann/detail/string_utils.hpp>
 #include <nlohmann/detail/value_t.hpp>
@@ -109,16 +108,8 @@ class binary_reader
     @brief create a binary reader
 
     @param[in] adapter  input adapter to read from
-    @param[in] format   the binary format to parse
-    @param[in] error_handler  how to treat text strings and object keys that
-               are not well-formed UTF-8; none of the supported formats
-               requires a decoder to reject those, so the default is to
-               @ref error_handler_t::keep them unchanged, as every binary
-               reader did before this parameter existed
     */
-    explicit binary_reader(InputAdapterType&& adapter, const input_format_t format = input_format_t::json,
+    explicit binary_reader(InputAdapterType&& adapter, const input_format_t format = input_format_t::json) noexcept : ia(std::move(adapter)), input_format(format)
-                           const error_handler_t error_handler = error_handler_t::keep) noexcept
-        : ia(std::move(adapter)), input_format(format), error_handler(error_handler)
     {
         (void)detail::is_sax_static_asserts<SAX, BasicJsonType> {};
     }
@@ -437,7 +428,7 @@ class binary_reader
     {
         if (get_bson_cstr_bulk(result, std::integral_constant<bool, bulk_scan> {}))
         {
-            return check_string_utf8(result, "key");
+            return true;
         }
 
         auto out = std::back_inserter(result);
@@ -450,7 +441,7 @@ class binary_reader
             }
             if (current == 0x00)
             {
-                return check_string_utf8(result, "key");
+                return true;
             }
             *out++ = static_cast<typename string_t::value_type>(current);
         }
@@ -531,7 +522,7 @@ class binary_reader
                                             "string"), nullptr));
         }
 
-        return check_string_utf8(result, "string");
+        return true;
     }
 
     /*!
@@ -1158,7 +1149,7 @@ class binary_reader
 
     @return whether string creation completed
     */
-    bool get_cbor_string(string_t& result, const char* context = "string")
+    bool get_cbor_string(string_t& result)
     {
         // number of indefinite-length strings that have been opened and not
         // closed yet. RFC 8949, Section 3.2.3 does not permit nesting them,
@@ -1188,7 +1179,7 @@ class binary_reader
             {
                 if (--open == 0)
                 {
-                    return check_string_utf8(result, context);
+                    return true;
                 }
                 get();
                 continue;
@@ -1201,7 +1192,7 @@ class binary_reader
 
             if (open == 0)
             {
-                return check_string_utf8(result, context);
+                return true;
             }
 
             get();
@@ -1225,7 +1216,7 @@ class binary_reader
         // EOF and major type 3 (text string) are left to get_cbor_string
         if (current == char_traits<char_type>::eof() || (static_cast<unsigned int>(current) & 0xE0u) == 0x60u)
         {
-            return get_cbor_string(result, "key");
+            return get_cbor_string(result);
         }
 
         const char* found = nullptr;
@@ -2013,7 +2004,7 @@ class binary_reader
 
     @return whether string creation completed
     */
-    bool get_msgpack_string(string_t& result, const char* context = "string")
+    bool get_msgpack_string(string_t& result)
     {
         if (JSON_HEDLEY_UNLIKELY(!unexpect_eof(input_format_t::msgpack, "string")))
         {
@@ -2056,25 +2047,25 @@ class binary_reader
             case 0xBE:
             case 0xBF:
             {
-                return get_string(input_format_t::msgpack, static_cast<unsigned int>(current) & 0x1Fu, result) && check_string_utf8(result, context);
+                return get_string(input_format_t::msgpack, static_cast<unsigned int>(current) & 0x1Fu, result);
             }
 
             case 0xD9: // str 8
             {
                 std::uint8_t len{};
-                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result) && check_string_utf8(result, context);
+                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result);
             }
 
             case 0xDA: // str 16
             {
                 std::uint16_t len{};
-                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result) && check_string_utf8(result, context);
+                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result);
             }
 
             case 0xDB: // str 32
             {
                 std::uint32_t len{};
-                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result) && check_string_utf8(result, context);
+                return get_number(input_format_t::msgpack, len) && get_string(input_format_t::msgpack, len, result);
             }
 
             default:
@@ -2152,7 +2143,7 @@ class binary_reader
                 // byte 0xC1 are left to get_msgpack_string
                 if (current == char_traits<char_type>::eof())
                 {
-                    return get_msgpack_string(result, "key");
+                    return get_msgpack_string(result);
                 }
                 if (current <= 0x7F || current >= 0xE0)
                 {
@@ -2168,7 +2159,7 @@ class binary_reader
                 }
                 else
                 {
-                    return get_msgpack_string(result, "key");
+                    return get_msgpack_string(result);
                 }
                 break;
         }
@@ -2414,7 +2405,7 @@ class binary_reader
                         if (top.is_object)
                         {
                             key.clear();
-                            if (JSON_HEDLEY_UNLIKELY(!get_ubjson_string(key, true, "key") || !sax->key(key)))
+                            if (JSON_HEDLEY_UNLIKELY(!get_ubjson_string(key) || !sax->key(key)))
                             {
                                 return false;
                             }
@@ -2436,7 +2427,7 @@ class binary_reader
                     if (top.is_object)
                     {
                         key.clear();
-                        if (JSON_HEDLEY_UNLIKELY(!get_ubjson_string(key, false, "key") || !sax->key(key)))
+                        if (JSON_HEDLEY_UNLIKELY(!get_ubjson_string(key, false) || !sax->key(key)))
                         {
                             return false;
                         }
@@ -2504,7 +2495,7 @@ class binary_reader
 
     @return whether string creation completed
     */
-    bool get_ubjson_string(string_t& result, const bool get_char = true, const char* context = "string")
+    bool get_ubjson_string(string_t& result, const bool get_char = true)
     {
         if (get_char)
         {
@@ -2525,31 +2516,31 @@ class binary_reader
             case 'U':
             {
                 std::uint8_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && get_string(input_format, len, result);
             }
 
             case 'i':
             {
                 std::int8_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'I':
             {
                 std::int16_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'l':
             {
                 std::int32_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'L':
             {
                 std::int64_t len{};
-                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && check_ubjson_string_length(len) && get_string(input_format, len, result);
             }
 
             case 'u':
@@ -2559,7 +2550,7 @@ class binary_reader
                     break;
                 }
                 std::uint16_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && get_string(input_format, len, result);
             }
 
             case 'm':
@@ -2569,7 +2560,7 @@ class binary_reader
                     break;
                 }
                 std::uint32_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && get_string(input_format, len, result);
             }
 
             case 'M':
@@ -2579,7 +2570,7 @@ class binary_reader
                     break;
                 }
                 std::uint64_t len{};
-                return get_number(input_format, len) && get_string(input_format, len, result) && check_string_utf8(result, context);
+                return get_number(input_format, len) && get_string(input_format, len, result);
             }
 
             default:
@@ -4040,50 +4031,27 @@ class binary_reader
                     const NumberType len,
                     string_t& result)
     {
-        // Strings are taken as is by default: none of CBOR (RFC 8949 §3.1
+        // get_bytes() appends to result, and CBOR indefinite-length strings
-        // leaves the choice to the decoder), MessagePack (whose spec
+        // collect all their chunks in the same result; validating only the
-        // explicitly allows a str object to contain an invalid byte
+        // newly read bytes keeps the check linear in the input size
-        // sequence), UBJSON, BJData, or BSON requires a decoder to reject
+        const std::size_t old_size = result.size();
-        // ill-formed UTF-8. Checking (and, with @ref error_handler_t::strict,
+        if (JSON_HEDLEY_UNLIKELY(!get_bytes(format, len, "string", result)))
-        // rejecting, or with `replace`/`ignore`, sanitizing) is opt-in via
+        {
-        // @ref error_handler, applied once the whole string (all chunks of
+            return false;
-        // an indefinite-length CBOR string included) has been assembled, by
-        // @ref check_string_utf8 at the call site.
-        return get_bytes(format, len, "string", result);
         }
 
-    /*!
+        // RFC 8949 (CBOR) §3.1 and the MessagePack/BSON/UBJSON specifications
-    @brief validate a decoded text string (value or object key) against @ref error_handler
+        // all require text strings to be valid UTF-8; reject anything else
-
+        // right here so malformed input is caught at decode time instead of
-    None of the binary formats requires a decoder to reject ill-formed UTF-8
+        // only surfacing later as a type_error.316 when the value is dumped
-    in a text string (see @ref get_string), so by default
+        // (which would defeat allow_exceptions=false / strict discarding).
-    (@ref error_handler_t::keep) this does nothing. A stricter
+        if (JSON_HEDLEY_UNLIKELY(!is_valid_utf8(result, old_size)))
-    @ref error_handler opts into the same well-formedness check @ref
-    serializer::dump_escaped_impl applies when dumping a string:
-    @ref error_handler_t::strict rejects ill-formed input with
-    parse_error.113 (honoring `allow_exceptions` via @a sax), while
-    @ref error_handler_t::replace / @ref error_handler_t::ignore sanitize
-    @a result in place, using the exact same rules.
-
-    @param[in,out] result  the already assembled string to check
-    @param[in] context     further context information (for diagnostics)
-    @return whether @a result is acceptable (always true for `keep`)
-    */
-    bool check_string_utf8(string_t& result, const char* context)
         {
-        if (error_handler == error_handler_t::keep || is_valid_utf8(result))
+            return sax->parse_error(chars_read, get_token_string(),
-        {
+                                    parse_error::create(113, chars_read,
-            return true;
+                                            exception_message(format, "invalid string: ill-formed UTF-8 byte", "string"), nullptr));
         }
 
-        if (error_handler == error_handler_t::strict)
-        {
-            auto last_token = get_token_string();
-            return sax->parse_error(chars_read, last_token, parse_error::create(113, chars_read,
-                                    exception_message(input_format, "invalid string: ill-formed UTF-8 byte", context), nullptr));
-        }
-
-        result = sanitize_utf8(result, error_handler);
         return true;
     }
 
@@ -4258,9 +4226,6 @@ class binary_reader
     /// input format
     const input_format_t input_format = input_format_t::json;
 
-    /// how to treat text strings/object keys that are not well-formed UTF-8
-    const error_handler_t error_handler = error_handler_t::keep;
-
     /// the SAX parser
     json_sax_t* sax = nullptr;
 

include/nlohmann/detail/output/binary_writer.hpp

@@ -26,7 +26,6 @@
 #include <nlohmann/detail/input/binary_reader.hpp>
 #include <nlohmann/detail/input/string_scan.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
 #include <nlohmann/detail/output/output_adapters.hpp>
 #include <nlohmann/detail/string_concat.hpp>
 #include <nlohmann/detail/string_utils.hpp>
@@ -94,12 +93,8 @@ class binary_writer
     @param[in] sink  output sink to write to (a value-type sink such as
                      output_vector_sink, or output_adapter_sink wrapping a
                      type-erased output adapter)
-    @param[in] error_handler_  how to treat a string value or object key that
-               is not valid UTF-8 (CBOR, UBJSON, BJData, and BSON only; never
-               consulted by @ref write_msgpack or @ref write_bon8)
     */
-    explicit binary_writer(OutputSinkType sink, const error_handler_t error_handler_ = error_handler_t::strict)
+    explicit binary_writer(OutputSinkType sink) : oa(std::move(sink))
-        : oa(std::move(sink)), error_handler(error_handler_)
     {}
 
     /*!
@@ -112,20 +107,14 @@ class binary_writer
     from one.
 
     @param[in] adapter  output adapter to write to
-    @param[in] error_handler_  how to treat a string value or object key that
-               is not valid UTF-8 (CBOR, UBJSON, BJData, and BSON only; never
-               consulted by @ref write_msgpack or @ref write_bon8)
     */
     template < typename SinkType = OutputSinkType,
                typename std::enable_if < std::is_constructible<SinkType, output_adapter_t<CharType>>::value, int >::type = 0 >
-    explicit binary_writer(output_adapter_t<CharType> adapter, const error_handler_t error_handler_ = error_handler_t::strict)
+    explicit binary_writer(output_adapter_t<CharType> adapter) : oa(SinkType(std::move(adapter)))
-        : oa(SinkType(std::move(adapter))), error_handler(error_handler_)
     {}
 
     /*!
     @param[in] j  JSON value to serialize
-    @throw type_error.316 if a string value or an object key is not valid
-           UTF-8
     @throw type_error.317 if @a j is not an object
     */
     void write_bson(const BasicJsonType& j)
@@ -156,8 +145,6 @@ class binary_writer
 
     /*!
     @param[in] j  JSON value to serialize
-    @throw type_error.316 if a string value or an object key is not valid
-           UTF-8
     */
     void write_cbor(const BasicJsonType& j)
     {
@@ -224,16 +211,13 @@ class binary_writer
 
             case value_t::string:
             {
-                string_t storage;
-                const string_t& value = sanitize_utf8_for_write(*j.m_data.m_value.string, j, storage);
-
                 // step 1: write control byte and the string length
-                write_cbor_head(0x60, value.size());
+                write_cbor_head(0x60, j.m_data.m_value.string->size());
 
                 // step 2: write the string
                 oa.write_characters(
-                      reinterpret_cast<const CharType*>(value.data()),
+                      reinterpret_cast<const CharType*>(j.m_data.m_value.string->data()),
-                      value.size());
+                      j.m_data.m_value.string->size());
                 break;
             }
 
@@ -303,17 +287,6 @@ class binary_writer
                 // step 2: write each element
                 for (const auto& el : *j.m_data.m_value.object)
                 {
-                    // el.first is checked here, against the object as
-                    // diagnostics context, because write_cbor(el.first)
-                    // converts it to a temporary basic_json that would be
-                    // used as the context instead; for error_handler_t::keep
-                    // and ::replace/::ignore the recursive write_cbor(el.first)
-                    // call below handles the key like any other string, so no
-                    // separate check is needed here for those
-                    if (error_handler == error_handler_t::strict)
-                    {
-                        check_utf8(el.first, j);
-                    }
                     write_cbor(el.first);
                     write_cbor(el.second);
                 }
@@ -656,8 +629,6 @@ class binary_writer
     @param[in] add_prefix  whether prefixes need to be used for this value
     @param[in] use_bjdata  whether write in BJData format, default is false
     @param[in] bjdata_version  which BJData version to use, default is draft2
-    @throw type_error.316 if a string value or an object key is not valid
-           UTF-8
     */
     void write_ubjson(const BasicJsonType& j, const bool use_count,
                       const bool use_type, const bool add_prefix = true,
@@ -707,17 +678,14 @@ class binary_writer
 
             case value_t::string:
             {
-                string_t storage;
-                const string_t& value = sanitize_utf8_for_write(*j.m_data.m_value.string, j, storage);
-
                 if (add_prefix)
                 {
                     oa.write_character(to_char_type('S'));
                 }
-                write_number_with_ubjson_prefix(value.size(), true, use_bjdata);
+                write_number_with_ubjson_prefix(j.m_data.m_value.string->size(), true, use_bjdata);
                 oa.write_characters(
-                      reinterpret_cast<const CharType*>(value.data()),
+                      reinterpret_cast<const CharType*>(j.m_data.m_value.string->data()),
-                      value.size());
+                      j.m_data.m_value.string->size());
                 break;
             }
 
@@ -872,12 +840,10 @@ class binary_writer
 
                 for (const auto& el : *j.m_data.m_value.object)
                 {
-                    string_t storage;
+                    write_number_with_ubjson_prefix(el.first.size(), true, use_bjdata);
-                    const string_t& key = sanitize_utf8_for_write(el.first, j, storage);
-                    write_number_with_ubjson_prefix(key.size(), true, use_bjdata);
                     oa.write_characters(
-                          reinterpret_cast<const CharType*>(key.data()),
+                          reinterpret_cast<const CharType*>(el.first.data()),
-                          key.size());
+                          el.first.size());
                     write_ubjson(el.second, use_count, use_type, prefix_required, use_bjdata, bjdata_version);
                 }
 
@@ -918,12 +884,8 @@ class binary_writer
     /*!
     @return The size of a BSON document entry header, including the id marker
             and the entry name size (and its null-terminator).
-    @throw out_of_range.409 if @a name contains U+0000, before anything is
-           written
-    @throw type_error.316 if @a name is not valid UTF-8, before anything is
-           written
     */
-    std::size_t calc_bson_entry_header_size(const string_t& name, const BasicJsonType& j)
+    static std::size_t calc_bson_entry_header_size(const string_t& name, const BasicJsonType& j)
     {
         const auto it = name.find(static_cast<typename string_t::value_type>(0));
         if (JSON_HEDLEY_UNLIKELY(it != BasicJsonType::string_t::npos))
@@ -931,10 +893,8 @@ class binary_writer
             JSON_THROW(out_of_range::create(409, concat("BSON key cannot contain code point U+0000 (at byte ", std::to_string(it), ")"), &j));
         }
 
-        string_t storage;
+        static_cast<void>(j);
-        const string_t& sanitized = sanitize_utf8_for_write(name, j, storage);
+        return /*id*/ 1ul + name.size() + /*zero-terminator*/1u;
-
-        return /*id*/ 1ul + sanitized.size() + /*zero-terminator*/1u;
     }
 
     /*!
@@ -954,28 +914,14 @@ class binary_writer
 
     /*!
     @brief Writes the given @a element_type and @a name to the output adapter
-
-    @a name has already been validated (and, for @ref error_handler_t::strict,
-    found well-formed) by @ref calc_bson_entry_header_size during the earlier
-    size pass, so only @ref error_handler_t::replace / @ref
-    error_handler_t::ignore need to sanitize it again here, to actually write
-    the bytes that size was computed from.
     */
     void write_bson_entry_header(const string_t& name,
                                  const std::uint8_t element_type)
     {
         oa.write_character(to_char_type(element_type));
-
+        oa.write_characters(
-        if (error_handler == error_handler_t::keep || error_handler == error_handler_t::strict || is_valid_utf8(name))
+              reinterpret_cast<const CharType*>(name.data()),
-        {
+              name.size());
-            oa.write_characters(reinterpret_cast<const CharType*>(name.data()), name.size());
-        }
-        else
-        {
-            const string_t sanitized = sanitize_utf8(name, error_handler);
-            oa.write_characters(reinterpret_cast<const CharType*>(sanitized.data()), sanitized.size());
-        }
-
         // the terminating null byte is written explicitly rather than taken
         // from the buffer, so that string_t::data() need not be null-terminated
         oa.write_character(to_char_type(0x00));
@@ -1003,50 +949,24 @@ class binary_writer
 
     /*!
     @return The size of the BSON-encoded string in @a value
-    @throw type_error.316 if @a value is not valid UTF-8, before anything is
-           written
-
-    @note The UTF-8 check is skipped if @a value is already too long for the
-          32-bit BSON length field (@ref to_bson_length rejects it later, once
-          the size of the whole document is known); this also keeps the check
-          from reading past a StringType that reports a size larger than what
-          it actually holds.
     */
-    std::size_t calc_bson_string_size(const string_t& value, const BasicJsonType& j)
+    static std::size_t calc_bson_string_size(const string_t& value)
     {
-        if (JSON_HEDLEY_LIKELY(value_in_range_of<std::int32_t>(value.size())))
-        {
-            string_t storage;
-            const string_t& sanitized = sanitize_utf8_for_write(value, j, storage);
-            return sizeof(std::int32_t) + sanitized.size() + 1ul;
-        }
         return sizeof(std::int32_t) + value.size() + 1ul;
     }
 
     /*!
     @brief Writes a BSON element with key @a name and string value @a value
-
-    @a value has already been validated (and, for @ref error_handler_t::strict,
-    found well-formed) by @ref calc_bson_string_size during the earlier size
-    pass, so only @ref error_handler_t::replace / @ref error_handler_t::ignore
-    need to sanitize it again here, to actually write the bytes that size was
-    computed from.
     */
     void write_bson_string(const string_t& name,
                            const string_t& value)
     {
         write_bson_entry_header(name, 0x02);
 
-        const bool sanitize = error_handler != error_handler_t::keep
+        write_number<std::int32_t>(to_bson_length(value.size() + 1ul), true);
-                              && error_handler != error_handler_t::strict
-                              && !is_valid_utf8(value);
-        const string_t sanitized = sanitize ? sanitize_utf8(value, error_handler) : string_t{};
-        const string_t& written = sanitize ? sanitized : value;
-
-        write_number<std::int32_t>(to_bson_length(written.size() + 1ul), true);
         oa.write_characters(
-              reinterpret_cast<const CharType*>(written.data()),
+              reinterpret_cast<const CharType*>(value.data()),
-              written.size());
+              value.size());
         // the terminating null byte is written explicitly rather than taken
         // from the buffer, so that string_t::data() need not be null-terminated
         oa.write_character(to_char_type(0x00));
@@ -1160,10 +1080,8 @@ class binary_writer
             is neither an object nor an array
     @throw out_of_range.415 if @a j is binary with a subtype that does not fit
            into a byte, before anything is written
-    @throw type_error.316 if @a j is a string that is not valid UTF-8, before
-           anything is written
     */
-    std::size_t calc_bson_value_size(const BasicJsonType& j)
+    static std::size_t calc_bson_value_size(const BasicJsonType& j)
     {
         switch (j.type())
         {
@@ -1183,7 +1101,7 @@ class binary_writer
                 return calc_bson_unsigned_size(j.m_data.m_value.number_unsigned);
 
             case value_t::string:
-                return calc_bson_string_size(*j.m_data.m_value.string, j);
+                return calc_bson_string_size(*j.m_data.m_value.string);
 
             case value_t::null:
                 return 0ul;
@@ -1296,10 +1214,8 @@ class binary_writer
            written
     @throw out_of_range.415 if a binary value's subtype does not fit into a
            byte, before anything is written
-    @throw type_error.316 if a string value or a key is not valid UTF-8,
-           before anything is written
     */
-    std::size_t calc_bson_sizes(const BasicJsonType& document, std::vector<std::size_t>& nested_sizes)
+    static std::size_t calc_bson_sizes(const BasicJsonType& document, std::vector<std::size_t>& nested_sizes)
     {
         // the object or array whose entries are being sized, and the ones it
         // is in; nothing is allocated unless the document nests
@@ -2176,7 +2092,7 @@ class binary_writer
     */
     void write_bon8_string(const string_t& s, bool& string_open, const BasicJsonType& context)
     {
-        check_utf8(s, context);
+        check_bon8_utf8(s, context);
 
         // a string that follows another string terminates it
         if (string_open)
@@ -2206,7 +2122,7 @@ class binary_writer
     @throw type_error.316 if @a s is not valid UTF-8; the message names the
            first byte of the first invalid or incomplete sequence
     */
-    static void check_utf8(const string_t& s, const BasicJsonType& context)
+    static void check_bon8_utf8(const string_t& s, const BasicJsonType& context)
     {
         static_cast<void>(context); // only used when exceptions are enabled
         const auto* data = reinterpret_cast<const unsigned char*>(s.data());
@@ -2217,59 +2133,6 @@ class binary_writer
         }
     }
 
-    /*!
-    @brief return @a s as it should be written, honoring @ref error_handler
-
-    Used by @ref write_cbor, @ref write_ubjson (and so @ref write_bjdata), and
-    the BSON writing functions for string values and object keys; never by
-    @ref write_msgpack or @ref write_bon8, which do not take an @ref
-    error_handler (MessagePack's spec allows a str object to contain
-    ill-formed UTF-8, and BON8 always validates, since UTF-8 lead bytes are
-    structural there).
-
-    - @ref error_handler_t::keep: @a s is returned unchanged, without even
-      checking it (the behavior of release 3.12.0 and earlier).
-    - @ref error_handler_t::strict: @ref check_utf8 is called, which throws
-      type_error.316 if @a s is not valid UTF-8.
-    - @ref error_handler_t::replace / @ref error_handler_t::ignore: @a s is
-      sanitized into @a storage with exactly the rules @ref
-      serializer::dump_escaped_impl uses, so that parsing what @ref
-      basic_json::dump produces for the same string and the same handler
-      yields the same result.
-
-    Well-formed input is never copied: this returns a reference to @a s
-    itself in every case but a sanitized `replace`/`ignore` one, so @a
-    storage must outlive the returned reference only then.
-
-    @param[in] s        the string (value or object key) to write
-    @param[in] context  the value @a s belongs to (for diagnostics)
-    @param[out] storage  backing storage for a sanitized copy
-
-    @return a reference to @a s, or to @a storage once it holds a sanitized copy
-    */
-    const string_t& sanitize_utf8_for_write(const string_t& s, const BasicJsonType& context, string_t& storage) const
-    {
-        switch (error_handler)
-        {
-            case error_handler_t::keep:
-                return s;
-
-            case error_handler_t::strict:
-                check_utf8(s, context);
-                return s;
-
-            case error_handler_t::replace:
-            case error_handler_t::ignore:
-            default:
-                if (is_valid_utf8(s))
-                {
-                    return s;
-                }
-                storage = sanitize_utf8(s, error_handler);
-                return storage;
-        }
-    }
-
     /*!
     @brief write an integer in the shortest encoding
 
@@ -2598,10 +2461,6 @@ class binary_writer
 
     /// the output
     OutputSinkType oa;
-
-    /// how to treat a string value or object key that is not valid UTF-8
-    /// (CBOR, UBJSON, BJData, and BSON only)
-    const error_handler_t error_handler = error_handler_t::strict;
 };
 
 }  // namespace detail

include/nlohmann/detail/output/error_handler.hpp

@@ -1,38 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-#pragma once
-
-#include <nlohmann/detail/abi_macros.hpp>
-
-NLOHMANN_JSON_NAMESPACE_BEGIN
-namespace detail
-{
-
-/// how to treat decoding errors
-///
-/// @ref basic_json::dump uses this to decide what to do with ill-formed
-/// UTF-8 while escaping a string, and the binary writers (@ref
-/// basic_json::to_cbor, @ref basic_json::to_ubjson, @ref
-/// basic_json::to_bjdata, @ref basic_json::to_bson) use it the same way for
-/// string values and object keys. The binary readers (@ref
-/// basic_json::from_cbor, @ref basic_json::from_msgpack, @ref
-/// basic_json::from_ubjson, @ref basic_json::from_bjdata, @ref
-/// basic_json::from_bson) use it to decide whether to check text strings
-/// and object keys for well-formed UTF-8 at all, since none of those
-/// formats requires a decoder to do so.
-enum class error_handler_t
-{
-    strict,  ///< throw a type_error/parse_error exception in case of invalid UTF-8
-    replace, ///< replace invalid UTF-8 sequences with U+FFFD
-    ignore,  ///< ignore invalid UTF-8 sequences
-    keep     ///< keep invalid UTF-8 sequences unchanged
-};
-
-}  // namespace detail
-NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/detail/output/serializer.hpp

@@ -27,7 +27,6 @@
 #include <nlohmann/detail/input/string_scan.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
 #include <nlohmann/detail/meta/cpp_future.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
 #include <nlohmann/detail/output/output_adapters.hpp>
 #include <nlohmann/detail/recursion_depth_limit.hpp>
 #include <nlohmann/detail/string_concat.hpp>
@@ -42,6 +41,14 @@ namespace detail
 // serialization //
 ///////////////////
 
+/// how to treat decoding errors
+enum class error_handler_t
+{
+    strict,  ///< throw a type_error exception in case of invalid UTF-8
+    replace, ///< replace invalid UTF-8 sequences with U+FFFD
+    ignore   ///< ignore invalid UTF-8 sequences
+};
+
 template<typename BasicJsonType>
 class serializer
 {
@@ -832,16 +839,6 @@ class serializer
                             // EnsureAscii parameter is used, non-ASCII characters
                             if ((codepoint <= 0x1F) || (EnsureAscii && (codepoint >= 0x7F)))
                             {
-                                if (EnsureAscii && error_handler == error_handler_t::keep)
-                                {
-                                    // this character was buffered as raw bytes
-                                    // below in case it turned out to be part of
-                                    // an ill-formed sequence (which is kept as
-                                    // is); now that it decoded to a well-formed
-                                    // code point, undo that and \u-escape it
-                                    // like any other character instead
-                                    bytes = bytes_after_last_accept;
-                                }
                                 if (codepoint <= 0xFFFF)
                                 {
                                     write_u_escape(bytes, static_cast<std::uint16_t>(codepoint));
@@ -940,44 +937,6 @@ class serializer
                             break;
                         }
 
-                        case error_handler_t::keep:
-                        {
-                            // the bytes of this (now abandoned) ill-formed
-                            // sequence seen so far are already buffered below
-                            // and are kept unchanged in the output
-                            if (undumped_chars > 0)
-                            {
-                                // the byte that ended the sequence may be OK
-                                // for itself (e.g., a quote that must still be
-                                // escaped, or the lead byte of a well-formed
-                                // code point), so read it again
-                                --i;
-                            }
-                            else
-                            {
-                                // a byte that cannot start a sequence (e.g.,
-                                // 0xFF or a stray continuation byte) is kept
-                                // as well
-                                string_buffer[bytes++] = s[i];
-                            }
-
-                            // write buffer and reset index; there must be 13 bytes
-                            // left, as this is the maximal number of bytes to be
-                            // written ("\uxxxx\uxxxx\0") for one code point
-                            if (string_buffer.size() - bytes < 13)
-                            {
-                                put_buffer(string_buffer, bytes);
-                                bytes = 0;
-                            }
-
-                            bytes_after_last_accept = bytes;
-                            undumped_chars = 0;
-
-                            // continue processing the string
-                            state = UTF8_ACCEPT;
-                            break;
-                        }
-
                         default:            // LCOV_EXCL_LINE
                             JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
                     }
@@ -986,12 +945,9 @@ class serializer
 
                 default:  // decode found yet incomplete multibyte code point
                 {
-                    if (!EnsureAscii || error_handler == error_handler_t::keep)
+                    if (!EnsureAscii)
                     {
-                        // code point will not be escaped (or will be kept as
+                        // code point will not be escaped - copy byte to buffer
-                        // is if it turns out to be ill-formed) - copy byte to
-                        // buffer; dropped again above if it decodes to a
-                        // well-formed code point that needs \u-escaping
                         string_buffer[bytes++] = s[i];
                     }
                     ++undumped_chars;
@@ -1042,14 +998,6 @@ class serializer
                     break;
                 }
 
-                case error_handler_t::keep:
-                {
-                    // write the ill-formed trailing bytes as is; they were
-                    // buffered above regardless of EnsureAscii
-                    put_buffer(string_buffer, bytes);
-                    break;
-                }
-
                 default:            // LCOV_EXCL_LINE
                     JSON_ASSERT(false); // NOLINT(cert-dcl03-c,hicpp-static-assert,misc-static-assert) LCOV_EXCL_LINE
             }

include/nlohmann/detail/string_utils.hpp

@@ -16,7 +16,6 @@
 
 #include <nlohmann/detail/abi_macros.hpp>
 #include <nlohmann/detail/macro_scope.hpp>
-#include <nlohmann/detail/output/error_handler.hpp>
 
 NLOHMANN_JSON_NAMESPACE_BEGIN
 namespace detail
@@ -118,14 +117,13 @@ This is a single-byte step of a "shift-based" UTF-8 decoder originally
 written by Björn Hoehrmann. See
 http://bjoern.hoehrmann.de/utf-8/decoder/dfa/ for details.
 
-The library checks UTF-8 well-formedness (RFC 3629, section 4) in three
+The library checks UTF-8 well-formedness (RFC 3629, section 4) in four
 places, which differ in speed, diagnostics, and how they read the input:
 
-- decode() below: the serializer, to escape and, in strict mode, reject
+- decode() and @ref is_valid_utf8 below: the serializer (to escape and, in
-  ill-formed UTF-8 when dumping a string. The CBOR, MessagePack, BSON,
+  strict mode, reject ill-formed UTF-8 when dumping a string) and the CBOR,
-  UBJSON and BJData readers do not use it: none of those specs requires a
+  MessagePack, BSON, UBJSON and BJData readers (to reject ill-formed UTF-8 in
-  decoder to reject ill-formed UTF-8 in text strings, so the readers keep
+  text strings at decode time).
-  the bytes as is and leave the check to dump() and the binary writers.
 - the per-lead-byte switch in lexer::scan_string(): JSON text, with a
   diagnostic for each kind of error.
 - validate_one_utf8() and valid_utf8_prefix() in string_scan.hpp: the lexer's
@@ -181,19 +179,19 @@ inline std::uint8_t decode(std::uint8_t& state, std::uint32_t& codep, const std:
 }
 
 /*!
-@brief check a string for well-formed UTF-8 (RFC 3629, section 4)
+@brief check whether a string consists solely of valid UTF-8
 
-Used by the binary readers (CBOR, MessagePack, UBJSON, BJData, BSON) when an
+Used by the CBOR/MessagePack/BSON/UBJSON binary readers to reject text
-@ref error_handler_t other than `keep` is requested for a text string value
+strings that are not valid UTF-8 at decode time (RFC 8949 §3.1 and the
-or object key: none of those formats requires a decoder to reject ill-formed
+MessagePack/BSON specifications all require text strings to be UTF-8), so
-UTF-8 on its own, so the check is opt-in there, unlike the JSON lexer and the
+that malformed input is caught immediately instead of only surfacing later
-serializer's @ref decode -based escaping, which always run it.
+as a type_error.316 when the resulting value is dumped.
 
 @param[in] s      the string to check
-@param[in] first  the index to start checking at
+@param[in] first  index of the first byte to check; the bytes before it are
-@return whether `s.substr(first)` is well-formed UTF-8
+                  assumed to have been validated already and to end on a
-
+                  code point boundary
-@sa @ref decode
+@return whether @a s (from index @a first on) is valid UTF-8
 */
 template<typename StringType>
 inline bool is_valid_utf8(const StringType& s, const std::size_t first = 0) noexcept
@@ -213,101 +211,5 @@ inline bool is_valid_utf8(const StringType& s, const std::size_t first = 0) noex
     return state == UTF8_ACCEPT;
 }
 
-/*!
-@brief sanitize a string with ill-formed UTF-8 for @ref error_handler_t::replace or @ref error_handler_t::ignore
-
-Replaces every maximal ill-formed subsequence with U+FFFD (`replace`) or
-drops it (`ignore`), using exactly the same boundaries @ref
-serializer::dump_escaped_impl uses while escaping a string: a byte that does
-not extend the sequence started by the previous byte(s) is reread as the
-start of a new one, instead of being swallowed along with them.
-
-@pre @a error_handler is @ref error_handler_t::replace or @ref error_handler_t::ignore
-@note Well-formed input is copied through unchanged, including bytes (e.g.
-      control characters or quotes) that @ref serializer::dump_escaped_impl
-      would itself escape; this function only concerns itself with
-      well-formedness, not with producing valid JSON text.
-
-@param[in] s              the string to sanitize
-@param[in] error_handler  @ref error_handler_t::replace or @ref error_handler_t::ignore
-
-@return @a s with every ill-formed subsequence replaced or removed
-
-@sa @ref decode
-*/
-template<typename StringType>
-inline StringType sanitize_utf8(const StringType& s, const error_handler_t error_handler)
-{
-    JSON_ASSERT(error_handler == error_handler_t::replace || error_handler == error_handler_t::ignore);
-
-    StringType result;
-    result.reserve(s.size());
-
-    std::uint32_t codepoint = 0;
-    std::uint8_t state = UTF8_ACCEPT;
-    // length of result after the last accepted code point
-    std::size_t result_len_after_last_accept = 0;
-    // whether bytes of an as yet unresolved sequence were already appended
-    bool pending = false;
-
-    for (std::size_t i = 0; i < s.size(); ++i)
-    {
-        switch (decode(state, codepoint, static_cast<std::uint8_t>(s[i])))
-        {
-            case UTF8_ACCEPT: // decode found a well-formed code point
-            {
-                result.push_back(s[i]);
-                result_len_after_last_accept = result.size();
-                pending = false;
-                break;
-            }
-
-            case UTF8_REJECT: // decode found an ill-formed byte
-            {
-                // in case we saw this byte for the first time, read it again,
-                // because it may be fine for itself, just not for the
-                // sequence that came before it
-                if (pending)
-                {
-                    --i;
-                }
-
-                // drop the bytes of the ill-formed sequence buffered below
-                result.resize(result_len_after_last_accept);
-
-                if (error_handler == error_handler_t::replace)
-                {
-                    result.append("\xEF\xBF\xBD");
-                    result_len_after_last_accept = result.size();
-                }
-
-                pending = false;
-                state = UTF8_ACCEPT;
-                break;
-            }
-
-            default: // decode found yet incomplete multibyte code point
-            {
-                result.push_back(s[i]);
-                pending = true;
-                break;
-            }
-        }
-    }
-
-    // the string ended with an incomplete sequence
-    if (state != UTF8_ACCEPT)
-    {
-        result.resize(result_len_after_last_accept);
-
-        if (error_handler == error_handler_t::replace)
-        {
-            result.append("\xEF\xBF\xBD");
-        }
-    }
-
-    return result;
-}
-
 }  // namespace detail
 NLOHMANN_JSON_NAMESPACE_END

include/nlohmann/json.hpp

@@ -201,10 +201,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     // used by the vector-returning to_* overloads
     template<typename CharType> using vector_binary_writer =
         ::nlohmann::detail::binary_writer<basic_json, CharType, ::nlohmann::detail::output_vector_sink<CharType>>;
-    template<typename CharType> static vector_binary_writer<CharType> vector_writer(
+    template<typename CharType> static vector_binary_writer<CharType> vector_writer(std::vector<CharType>& v)
-        std::vector<CharType>& v, const ::nlohmann::detail::error_handler_t error_handler = ::nlohmann::detail::error_handler_t::strict)
     {
-        return vector_binary_writer<CharType>(::nlohmann::detail::output_vector_sink<CharType>(v), error_handler);
+        return vector_binary_writer<CharType>(::nlohmann::detail::output_vector_sink<CharType>(v));
     }
 
   JSON_PRIVATE_UNLESS_TESTED:
@@ -764,6 +763,15 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         static_cast<void>(check_parents);
     }
 
+    // GCC 13 to at least 15 report a false -Warray-bounds error when set_parents()
+    // is inlined at -O3 right after a non-container value was created: the analysis
+    // does not use m_type to rule out the object/array branches and checks
+    // the std::map access against the allocation of, e.g., a string.
+    // See https://github.com/nlohmann/json/issues/5742 and #4819.
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+#endif
     void set_parents()
     {
 #if JSON_DIAGNOSTICS
@@ -800,6 +808,9 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
         }
 #endif
     }
+#if defined(__GNUC__) && !defined(__clang__)
+#pragma GCC diagnostic pop
+#endif
 
     iterator set_parents(iterator it, std::ptrdiff_t count_set_parents)
     {
@@ -5446,29 +5457,26 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
   public:
     /// @brief create a CBOR serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_cbor/
-    static std::vector<std::uint8_t> to_cbor(const basic_json& j,
+    static std::vector<std::uint8_t> to_cbor(const basic_json& j)
-            const error_handler_t error_handler = error_handler_t::strict)
     {
         std::vector<std::uint8_t> result;
         result.reserve(detail::binary_reserve_hint(j));
-        vector_writer(result, error_handler).write_cbor(j);
+        vector_writer(result).write_cbor(j);
         return result;
     }
 
     /// @brief create a CBOR serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_cbor/
-    static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o,
+    static void to_cbor(const basic_json& j, detail::output_adapter<std::uint8_t> o)
-                        const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<std::uint8_t>(o, error_handler).write_cbor(j);
+        binary_writer<std::uint8_t>(o).write_cbor(j);
     }
 
     /// @brief create a CBOR serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_cbor/
-    static void to_cbor(const basic_json& j, detail::output_adapter<char> o,
+    static void to_cbor(const basic_json& j, detail::output_adapter<char> o)
-                        const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<char>(o, error_handler).write_cbor(j);
+        binary_writer<char>(o).write_cbor(j);
     }
 
     /// @brief create a MessagePack serialization of a given JSON value
@@ -5499,31 +5507,28 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/to_ubjson/
     static std::vector<std::uint8_t> to_ubjson(const basic_json& j,
             const bool use_size = false,
-            const bool use_type = false,
+            const bool use_type = false)
-            const error_handler_t error_handler = error_handler_t::strict)
     {
         std::vector<std::uint8_t> result;
         result.reserve(detail::binary_reserve_hint(j));
-        vector_writer(result, error_handler).write_ubjson(j, use_size, use_type);
+        vector_writer(result).write_ubjson(j, use_size, use_type);
         return result;
     }
 
     /// @brief create a UBJSON serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_ubjson/
     static void to_ubjson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
-                          const bool use_size = false, const bool use_type = false,
+                          const bool use_size = false, const bool use_type = false)
-                          const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<std::uint8_t>(o, error_handler).write_ubjson(j, use_size, use_type);
+        binary_writer<std::uint8_t>(o).write_ubjson(j, use_size, use_type);
     }
 
     /// @brief create a UBJSON serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_ubjson/
     static void to_ubjson(const basic_json& j, detail::output_adapter<char> o,
-                          const bool use_size = false, const bool use_type = false,
+                          const bool use_size = false, const bool use_type = false)
-                          const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<char>(o, error_handler).write_ubjson(j, use_size, use_type);
+        binary_writer<char>(o).write_ubjson(j, use_size, use_type);
     }
 
     /// @brief create a BJData serialization of a given JSON value
@@ -5531,12 +5536,11 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static std::vector<std::uint8_t> to_bjdata(const basic_json& j,
             const bool use_size = false,
             const bool use_type = false,
-            const bjdata_version_t version = bjdata_version_t::draft2,
+            const bjdata_version_t version = bjdata_version_t::draft2)
-            const error_handler_t error_handler = error_handler_t::strict)
     {
         std::vector<std::uint8_t> result;
         result.reserve(detail::binary_reserve_hint(j));
-        vector_writer(result, error_handler).write_ubjson(j, use_size, use_type, true, true, version);
+        vector_writer(result).write_ubjson(j, use_size, use_type, true, true, version);
         return result;
     }
 
@@ -5544,47 +5548,42 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     /// @sa https://json.nlohmann.me/api/basic_json/to_bjdata/
     static void to_bjdata(const basic_json& j, detail::output_adapter<std::uint8_t> o,
                           const bool use_size = false, const bool use_type = false,
-                          const bjdata_version_t version = bjdata_version_t::draft2,
+                          const bjdata_version_t version = bjdata_version_t::draft2)
-                          const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<std::uint8_t>(o, error_handler).write_ubjson(j, use_size, use_type, true, true, version);
+        binary_writer<std::uint8_t>(o).write_ubjson(j, use_size, use_type, true, true, version);
     }
 
     /// @brief create a BJData serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_bjdata/
     static void to_bjdata(const basic_json& j, detail::output_adapter<char> o,
                           const bool use_size = false, const bool use_type = false,
-                          const bjdata_version_t version = bjdata_version_t::draft2,
+                          const bjdata_version_t version = bjdata_version_t::draft2)
-                          const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<char>(o, error_handler).write_ubjson(j, use_size, use_type, true, true, version);
+        binary_writer<char>(o).write_ubjson(j, use_size, use_type, true, true, version);
     }
 
     /// @brief create a BSON serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_bson/
-    static std::vector<std::uint8_t> to_bson(const basic_json& j,
+    static std::vector<std::uint8_t> to_bson(const basic_json& j)
-            const error_handler_t error_handler = error_handler_t::strict)
     {
         std::vector<std::uint8_t> result;
         result.reserve(detail::binary_reserve_hint(j));
-        vector_writer(result, error_handler).write_bson(j);
+        vector_writer(result).write_bson(j);
         return result;
     }
 
     /// @brief create a BSON serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_bson/
-    static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o,
+    static void to_bson(const basic_json& j, detail::output_adapter<std::uint8_t> o)
-                        const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<std::uint8_t>(o, error_handler).write_bson(j);
+        binary_writer<std::uint8_t>(o).write_bson(j);
     }
 
     /// @brief create a BSON serialization of a given JSON value
     /// @sa https://json.nlohmann.me/api/basic_json/to_bson/
-    static void to_bson(const basic_json& j, detail::output_adapter<char> o,
+    static void to_bson(const basic_json& j, detail::output_adapter<char> o)
-                        const error_handler_t error_handler = error_handler_t::strict)
     {
-        binary_writer<char>(o, error_handler).write_bson(j);
+        binary_writer<char>(o).write_bson(j);
     }
 
     /// @brief create a BON8 serialization of a given JSON value
@@ -5618,13 +5617,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_cbor(InputType&& i,
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
-                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-                                const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor, error_handler).sax_parse(&sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor).sax_parse(&sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5639,13 +5637,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     static basic_json from_cbor(IteratorType first, SentinelType last,
                                 const bool strict = true,
                                 const bool allow_exceptions = true,
-                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error,
+                                const cbor_tag_handler_t tag_handler = cbor_tag_handler_t::error)
-                                const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor, error_handler).sax_parse(&sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::cbor).sax_parse(&sdp, strict, tag_handler)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5687,13 +5684,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_msgpack(InputType&& i,
                                    const bool strict = true,
-                                   const bool allow_exceptions = true,
+                                   const bool allow_exceptions = true)
-                                   const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5707,13 +5703,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_msgpack(IteratorType first, SentinelType last,
                                    const bool strict = true,
-                                   const bool allow_exceptions = true,
+                                   const bool allow_exceptions = true)
-                                   const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::msgpack).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5753,13 +5748,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_ubjson(InputType&& i,
                                   const bool strict = true,
-                                  const bool allow_exceptions = true,
+                                  const bool allow_exceptions = true)
-                                  const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5773,13 +5767,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_ubjson(IteratorType first, SentinelType last,
                                   const bool strict = true,
-                                  const bool allow_exceptions = true,
+                                  const bool allow_exceptions = true)
-                                  const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::ubjson).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5819,13 +5812,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_bjdata(InputType&& i,
                                   const bool strict = true,
-                                  const bool allow_exceptions = true,
+                                  const bool allow_exceptions = true)
-                                  const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5839,13 +5831,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_bjdata(IteratorType first, SentinelType last,
                                   const bool strict = true,
-                                  const bool allow_exceptions = true,
+                                  const bool allow_exceptions = true)
-                                  const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bjdata).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5895,13 +5886,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_bson(InputType&& i,
                                 const bool strict = true,
-                                const bool allow_exceptions = true,
+                                const bool allow_exceptions = true)
-                                const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::forward<InputType>(i));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }
@@ -5915,13 +5905,12 @@ class basic_json // NOLINT(cppcoreguidelines-special-member-functions,hicpp-spec
     JSON_HEDLEY_WARN_UNUSED_RESULT
     static basic_json from_bson(IteratorType first, SentinelType last,
                                 const bool strict = true,
-                                const bool allow_exceptions = true,
+                                const bool allow_exceptions = true)
-                                const error_handler_t error_handler = error_handler_t::keep)
     {
         basic_json result;
         auto ia = detail::input_adapter(std::move(first), std::move(last));
         detail::json_sax_dom_parser<basic_json, decltype(ia)> sdp(result, allow_exceptions);
-        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson, error_handler).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
+        if (!binary_reader<decltype(ia)>(std::move(ia), input_format_t::bson).sax_parse(&sdp, strict)) // cppcheck-suppress[accessMoved]
         {
             result = value_t::discarded;
         }

tests/CMakeLists.txt

@@ -139,6 +139,11 @@ json_test_set_test_options(test-unicode4 TEST_PROPERTIES TIMEOUT 3000)
 # only the #972 regression test needs thirdparty/fifo_map on its include path
 json_test_set_test_options(test-regression1 LINK_LIBRARIES fifo_map_include)
 
+# GCC's false -Warray-bounds error with JSON_DIAGNOSTICS only shows up when optimizing (#5742)
+json_test_set_test_options(test-diagnostics-optimized
+    COMPILE_OPTIONS $<$<CXX_COMPILER_ID:GNU>:-O3 -Werror=array-bounds>
+)
+
 #############################################################################
 # add unit tests
 #############################################################################

tests/src/unit-binary_utf8_error_handler.cpp

@@ -1,346 +0,0 @@
-//     __ _____ _____ _____
-//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
-// |  |  |__   |  |  | | | |  version 3.12.0
-// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
-//
-// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
-// SPDX-License-Identifier: MIT
-
-#include "doctest_compatibility.h"
-
-#include <nlohmann/json.hpp>
-using nlohmann::json;
-
-#include <string>
-#include <vector>
-
-namespace
-{
-
-struct ill_formed_case
-{
-    const char* name;
-    std::string bytes;
-};
-
-// RFC 3629 ill-formed sequences used throughout this file, plus one
-// well-formed sequence for contrast
-const std::vector<ill_formed_case> ill_formed_cases =
-{
-    {"overlong", "\xC0\xAE"},
-    {"lone_0xFF", "\xFF"},
-    {"truncated", "\xE2\x82"},
-    {"surrogate", "\xED\xA0\x80"},
-};
-
-const std::string valid_sequence = "\xC3\xA9"; // U+00E9, "é"
-
-using eh = json::error_handler_t;
-const std::vector<eh> all_handlers = {eh::strict, eh::replace, eh::ignore, eh::keep};
-
-// what dump()+parse() produces for a sanitizing error_handler; this is the
-// ground truth every binary writer/reader is checked against
-std::string dump_and_parse(const std::string& raw, eh error_handler)
-{
-    return json::parse(json(raw).dump(-1, ' ', false, error_handler)).get<std::string>();
-}
-
-} // namespace
-
-TEST_CASE("UTF-8 error_handler for the binary readers and writers")
-{
-    SECTION("writers: string value")
-    {
-        for (const auto& c : ill_formed_cases)
-        {
-            CAPTURE(c.name);
-            const json jval = c.bytes;
-
-            CHECK_THROWS_AS(json::to_cbor(jval, eh::strict), json::type_error&);
-            CHECK_THROWS_AS(json::to_ubjson(jval, false, false, eh::strict), json::type_error&);
-            CHECK_THROWS_AS(json::to_bjdata(jval, false, false, json::bjdata_version_t::draft2, eh::strict), json::type_error&);
-            {
-                json jobj;
-                jobj["k"] = jval;
-                CHECK_THROWS_AS(json::to_bson(jobj, eh::strict), json::type_error&);
-            }
-
-            for (const auto h :
-                    {
-                        eh::replace, eh::ignore
-                    })
-            {
-                CAPTURE(static_cast<int>(h));
-                const std::string expected = dump_and_parse(c.bytes, h);
-
-                CHECK(json::from_cbor(json::to_cbor(jval, h)).get<std::string>() == expected);
-                CHECK(json::from_ubjson(json::to_ubjson(jval, false, false, h)).get<std::string>() == expected);
-                CHECK(json::from_bjdata(json::to_bjdata(jval, false, false, json::bjdata_version_t::draft2, h)).get<std::string>() == expected);
-                {
-                    json jobj;
-                    jobj["k"] = jval;
-                    const auto bytes = json::to_bson(jobj, h);
-                    CHECK(json::from_bson(bytes)["k"].get<std::string>() == expected);
-                }
-            }
-
-            // keep: the writer passes the ill-formed bytes through unchanged,
-            // exactly as every binary writer did before this parameter existed
-            CHECK(json::from_cbor(json::to_cbor(jval, eh::keep)).get<std::string>() == c.bytes);
-            CHECK(json::from_ubjson(json::to_ubjson(jval, false, false, eh::keep)).get<std::string>() == c.bytes);
-            CHECK(json::from_bjdata(json::to_bjdata(jval, false, false, json::bjdata_version_t::draft2, eh::keep)).get<std::string>() == c.bytes);
-            {
-                json jobj;
-                jobj["k"] = jval;
-                const auto bytes = json::to_bson(jobj, eh::keep);
-                CHECK(json::from_bson(bytes)["k"].get<std::string>() == c.bytes);
-            }
-        }
-    }
-
-    SECTION("writers: object key")
-    {
-        for (const auto& c : ill_formed_cases)
-        {
-            CAPTURE(c.name);
-            json jobj;
-            jobj[c.bytes] = 1;
-
-            CHECK_THROWS_AS(json::to_cbor(jobj, eh::strict), json::type_error&);
-            CHECK_THROWS_AS(json::to_ubjson(jobj, false, false, eh::strict), json::type_error&);
-            CHECK_THROWS_AS(json::to_bjdata(jobj, false, false, json::bjdata_version_t::draft2, eh::strict), json::type_error&);
-            CHECK_THROWS_AS(json::to_bson(jobj, eh::strict), json::type_error&);
-
-            for (const auto h :
-                    {
-                        eh::replace, eh::ignore
-                    })
-            {
-                CAPTURE(static_cast<int>(h));
-                const std::string expected = dump_and_parse(c.bytes, h);
-
-                CHECK(json::from_cbor(json::to_cbor(jobj, h)).begin().key() == expected);
-                CHECK(json::from_ubjson(json::to_ubjson(jobj, false, false, h)).begin().key() == expected);
-                CHECK(json::from_bjdata(json::to_bjdata(jobj, false, false, json::bjdata_version_t::draft2, h)).begin().key() == expected);
-                CHECK(json::from_bson(json::to_bson(jobj, h)).begin().key() == expected);
-            }
-
-            // keep: object keys round-trip unchanged too
-            CHECK(json::from_cbor(json::to_cbor(jobj, eh::keep)).begin().key() == c.bytes);
-            CHECK(json::from_ubjson(json::to_ubjson(jobj, false, false, eh::keep)).begin().key() == c.bytes);
-            CHECK(json::from_bjdata(json::to_bjdata(jobj, false, false, json::bjdata_version_t::draft2, eh::keep)).begin().key() == c.bytes);
-            CHECK(json::from_bson(json::to_bson(jobj, eh::keep)).begin().key() == c.bytes);
-        }
-    }
-
-    SECTION("readers: string value")
-    {
-        for (const auto& c : ill_formed_cases)
-        {
-            CAPTURE(c.name);
-
-            // bytes produced the lenient (keep) way, as any binary reader
-            // accepted them before this parameter existed
-            const auto cbor_bytes = json::to_cbor(json(c.bytes), eh::keep);
-            const auto msgpack_bytes = json::to_msgpack(json(c.bytes)); // to_msgpack has no error_handler; always pass-through
-            const auto ubjson_bytes = json::to_ubjson(json(c.bytes), false, false, eh::keep);
-            const auto bjdata_bytes = json::to_bjdata(json(c.bytes), false, false, json::bjdata_version_t::draft2, eh::keep);
-            const auto bson_bytes = [&c]
-            {
-                json jobj;
-                jobj["k"] = c.bytes;
-                return json::to_bson(jobj, eh::keep);
-            }();
-
-            // keep (the default): bytes are kept unchanged
-            CHECK(json::from_cbor(cbor_bytes).get<std::string>() == c.bytes);
-            CHECK(json::from_msgpack(msgpack_bytes).get<std::string>() == c.bytes);
-            CHECK(json::from_ubjson(ubjson_bytes).get<std::string>() == c.bytes);
-            CHECK(json::from_bjdata(bjdata_bytes).get<std::string>() == c.bytes);
-            CHECK(json::from_bson(bson_bytes)["k"].get<std::string>() == c.bytes);
-
-            // strict: parse_error.113, discarded (not thrown) when allow_exceptions is false
-            CHECK_THROWS_AS(json::from_cbor(cbor_bytes, true, true, json::cbor_tag_handler_t::error, eh::strict), json::parse_error&);
-            CHECK(json::from_cbor(cbor_bytes, true, false, json::cbor_tag_handler_t::error, eh::strict).is_discarded());
-            CHECK_THROWS_AS(json::from_msgpack(msgpack_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK(json::from_msgpack(msgpack_bytes, true, false, eh::strict).is_discarded());
-            CHECK_THROWS_AS(json::from_ubjson(ubjson_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK(json::from_ubjson(ubjson_bytes, true, false, eh::strict).is_discarded());
-            CHECK_THROWS_AS(json::from_bjdata(bjdata_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK(json::from_bjdata(bjdata_bytes, true, false, eh::strict).is_discarded());
-            CHECK_THROWS_AS(json::from_bson(bson_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK(json::from_bson(bson_bytes, true, false, eh::strict).is_discarded());
-
-            // replace / ignore: match what dump() would have sanitized the same bytes to
-            for (const auto h :
-                    {
-                        eh::replace, eh::ignore
-                    })
-            {
-                CAPTURE(static_cast<int>(h));
-                const std::string expected = dump_and_parse(c.bytes, h);
-
-                CHECK(json::from_cbor(cbor_bytes, true, true, json::cbor_tag_handler_t::error, h).get<std::string>() == expected);
-                CHECK(json::from_msgpack(msgpack_bytes, true, true, h).get<std::string>() == expected);
-                CHECK(json::from_ubjson(ubjson_bytes, true, true, h).get<std::string>() == expected);
-                CHECK(json::from_bjdata(bjdata_bytes, true, true, h).get<std::string>() == expected);
-                CHECK(json::from_bson(bson_bytes, true, true, h)["k"].get<std::string>() == expected);
-            }
-        }
-    }
-
-    SECTION("readers: object key")
-    {
-        for (const auto& c : ill_formed_cases)
-        {
-            CAPTURE(c.name);
-
-            json jobj;
-            jobj[c.bytes] = 1;
-            const auto cbor_bytes = json::to_cbor(jobj, eh::keep);
-            const auto msgpack_bytes = json::to_msgpack(jobj);
-            const auto ubjson_bytes = json::to_ubjson(jobj, false, false, eh::keep);
-            const auto bjdata_bytes = json::to_bjdata(jobj, false, false, json::bjdata_version_t::draft2, eh::keep);
-            const auto bson_bytes = json::to_bson(jobj, eh::keep);
-
-            CHECK(json::from_cbor(cbor_bytes).begin().key() == c.bytes);
-            CHECK(json::from_msgpack(msgpack_bytes).begin().key() == c.bytes);
-            CHECK(json::from_ubjson(ubjson_bytes).begin().key() == c.bytes);
-            CHECK(json::from_bjdata(bjdata_bytes).begin().key() == c.bytes);
-            CHECK(json::from_bson(bson_bytes).begin().key() == c.bytes);
-
-            CHECK_THROWS_AS(json::from_cbor(cbor_bytes, true, true, json::cbor_tag_handler_t::error, eh::strict), json::parse_error&);
-            CHECK_THROWS_AS(json::from_msgpack(msgpack_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK_THROWS_AS(json::from_ubjson(ubjson_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK_THROWS_AS(json::from_bjdata(bjdata_bytes, true, true, eh::strict), json::parse_error&);
-            CHECK_THROWS_AS(json::from_bson(bson_bytes, true, true, eh::strict), json::parse_error&);
-
-            for (const auto h :
-                    {
-                        eh::replace, eh::ignore
-                    })
-            {
-                CAPTURE(static_cast<int>(h));
-                const std::string expected = dump_and_parse(c.bytes, h);
-
-                CHECK(json::from_cbor(cbor_bytes, true, true, json::cbor_tag_handler_t::error, h).begin().key() == expected);
-                CHECK(json::from_msgpack(msgpack_bytes, true, true, h).begin().key() == expected);
-                CHECK(json::from_ubjson(ubjson_bytes, true, true, h).begin().key() == expected);
-                CHECK(json::from_bjdata(bjdata_bytes, true, true, h).begin().key() == expected);
-                CHECK(json::from_bson(bson_bytes, true, true, h).begin().key() == expected);
-            }
-        }
-    }
-
-    SECTION("well-formed UTF-8 is unaffected by error_handler")
-    {
-        const json jval = valid_sequence;
-        json jobj;
-        jobj[valid_sequence] = valid_sequence;
-
-        for (const auto h : all_handlers)
-        {
-            CAPTURE(static_cast<int>(h));
-
-            CHECK(json::from_cbor(json::to_cbor(jval, h)).get<std::string>() == valid_sequence);
-            CHECK(json::from_ubjson(json::to_ubjson(jval, false, false, h)).get<std::string>() == valid_sequence);
-            CHECK(json::from_bjdata(json::to_bjdata(jval, false, false, json::bjdata_version_t::draft2, h)).get<std::string>() == valid_sequence);
-            CHECK(json::from_bson(json::to_bson(jobj, h)).begin().key() == valid_sequence);
-
-            CHECK(json::from_cbor(json::to_cbor(jval, eh::keep), true, true, json::cbor_tag_handler_t::error, h).get<std::string>() == valid_sequence);
-            CHECK(json::from_msgpack(json::to_msgpack(jval), true, true, h).get<std::string>() == valid_sequence);
-        }
-    }
-
-    SECTION("dump() with error_handler_t::keep writes raw bytes as is")
-    {
-        for (const auto& c : ill_formed_cases)
-        {
-            CAPTURE(c.name);
-
-            const json jval = c.bytes;
-            const std::string dumped = jval.dump(-1, ' ', false, eh::keep);
-            CHECK(dumped.find(c.bytes) != std::string::npos);
-
-            // even with ensure_ascii, the ill-formed bytes are written as is
-            const std::string dumped_ascii = jval.dump(-1, ' ', true, eh::keep);
-            CHECK(dumped_ascii.find(c.bytes) != std::string::npos);
-        }
-
-        // well-formed characters around an ill-formed sequence are still
-        // escaped as usual under ensure_ascii
-        const json mixed = valid_sequence + ill_formed_cases[1].bytes; // "é" + lone 0xFF
-        const std::string dumped_mixed = mixed.dump(-1, ' ', true, eh::keep);
-        CHECK(dumped_mixed.find("\\u00e9") != std::string::npos);
-        CHECK(dumped_mixed.find(ill_formed_cases[1].bytes) != std::string::npos);
-
-        // the byte that ends an ill-formed sequence is read again, so a quote,
-        // a backslash, or a control character after it is still escaped, and
-        // a well-formed code point after it is escaped under ensure_ascii
-        for (const bool ensure_ascii :
-                {
-                    false, true
-                })
-        {
-            CAPTURE(ensure_ascii);
-            CHECK(json("\xC3\"").dump(-1, ' ', ensure_ascii, eh::keep) == "\"\xC3\\\"\"");
-            CHECK(json("\xC3\\").dump(-1, ' ', ensure_ascii, eh::keep) == "\"\xC3\\\\\"");
-            CHECK(json("\xC3\n").dump(-1, ' ', ensure_ascii, eh::keep) == "\"\xC3\\n\"");
-            CHECK(json("\xE2\x82\"").dump(-1, ' ', ensure_ascii, eh::keep) == "\"\xE2\x82\\\"\"");
-            CHECK(json("\xFF\"").dump(-1, ' ', ensure_ascii, eh::keep) == "\"\xFF\\\"\"");
-            CHECK(json("a\xE2\x82").dump(-1, ' ', ensure_ascii, eh::keep) == "\"a\xE2\x82\"");
-        }
-        CHECK(json("\xC3\xC3\xA9").dump(-1, ' ', false, eh::keep) == "\"\xC3\xC3\xA9\"");
-        CHECK(json("\xC3\xC3\xA9").dump(-1, ' ', true, eh::keep) == "\"\xC3\\u00e9\"");
-    }
-
-    SECTION("to_msgpack and to_bon8 are not affected by error_handler")
-    {
-        const json jval = ill_formed_cases[1].bytes; // lone 0xFF
-
-        // to_msgpack has no error_handler parameter; the bytes are always
-        // passed through, as MessagePack's spec allows
-        CHECK(json::from_msgpack(json::to_msgpack(jval)).get<std::string>() == ill_formed_cases[1].bytes);
-
-        // to_bon8 has no error_handler parameter either; UTF-8 is structural
-        // for BON8, so it always rejects ill-formed input
-        CHECK_THROWS_AS(json::to_bon8(jval), json::type_error&);
-    }
-
-    SECTION("allow_exceptions=false with error_handler_t::strict discards the value")
-    {
-        const auto bytes = json::to_cbor(json(ill_formed_cases[0].bytes), eh::keep);
-        const json result = json::from_cbor(bytes, true, false, json::cbor_tag_handler_t::error, eh::strict);
-        CHECK(result.is_discarded());
-    }
-
-    SECTION("default parameters are unchanged")
-    {
-        const json jval = ill_formed_cases[0].bytes;
-
-        // to_*: the default error_handler is strict, so ill-formed input still throws
-        CHECK_THROWS_AS(json::to_cbor(jval), json::type_error&);
-        CHECK_THROWS_AS(json::to_ubjson(jval), json::type_error&);
-        CHECK_THROWS_AS(json::to_bjdata(jval), json::type_error&);
-        {
-            json jobj;
-            jobj["k"] = jval;
-            CHECK_THROWS_AS(json::to_bson(jobj), json::type_error&);
-        }
-
-        // from_*: the default error_handler is keep, so ill-formed bytes are
-        // still accepted unchanged, exactly as in release 3.12.0
-        const auto cbor_bytes = json::to_cbor(jval, eh::keep);
-        CHECK(json::from_cbor(cbor_bytes).get<std::string>() == ill_formed_cases[0].bytes);
-        const auto ubjson_bytes = json::to_ubjson(jval, false, false, eh::keep);
-        CHECK(json::from_ubjson(ubjson_bytes).get<std::string>() == ill_formed_cases[0].bytes);
-        const auto bjdata_bytes = json::to_bjdata(jval, false, false, json::bjdata_version_t::draft2, eh::keep);
-        CHECK(json::from_bjdata(bjdata_bytes).get<std::string>() == ill_formed_cases[0].bytes);
-        const auto msgpack_bytes = json::to_msgpack(jval);
-        CHECK(json::from_msgpack(msgpack_bytes).get<std::string>() == ill_formed_cases[0].bytes);
-        json bson_obj;
-        bson_obj["k"] = jval;
-        const auto bson_bytes = json::to_bson(bson_obj, eh::keep);
-        CHECK(json::from_bson(bson_bytes)["k"].get<std::string>() == ill_formed_cases[0].bytes);
-    }
-}

tests/src/unit-bjdata.cpp

@@ -3907,41 +3907,6 @@ TEST_CASE("Universal Binary JSON Specification Examples 1")
             CHECK(json::to_bjdata(j) == v);
             CHECK(json::from_bjdata(v) == j);
         }
-
-        SECTION("ill-formed UTF-8 (see #5529, #5651)")
-        {
-            // none of the binary format specs requires a decoder to reject
-            // ill-formed UTF-8 in a text string, so a value whose bytes are
-            // not valid UTF-8 (0xC0 0xAE is an overlong encoding of '.')
-            // round-trips byte for byte as a string value; to_bjdata() is
-            // strict, so such a value cannot be written back
-            const std::vector<uint8_t> v = {'S', 'i', 2, 0xc0, 0xae};
-            json j;
-            CHECK_NOTHROW(j = json::from_bjdata(v));
-            REQUIRE(j.is_string());
-            CHECK(j.get_ref<const json::string_t&>() == std::string("\xc0\xae"));
-            CHECK_THROWS_AS(j.dump(), json::type_error&);
-            CHECK_THROWS_AS(json::to_bjdata(j), json::type_error&);
-
-            // the same bytes as an object key round-trip as well
-            const std::vector<uint8_t> v_key = {'{', 'i', 2, 0xc0, 0xae, 'i', 1, '}'};
-            json j_key;
-            CHECK_NOTHROW(j_key = json::from_bjdata(v_key));
-            REQUIRE(j_key.is_object());
-            CHECK(j_key.contains(std::string("\xc0\xae")));
-            CHECK_THROWS_AS(json::to_bjdata(j_key), json::type_error&);
-
-            CHECK_THROWS_WITH_AS(json::to_bjdata(json("\xFF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-            // a truncated multi-byte sequence
-            CHECK_THROWS_WITH_AS(json::to_bjdata(json("\xC3")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC3", json::type_error&);
-            // an encoded surrogate half (U+D800)
-            CHECK_THROWS_WITH_AS(json::to_bjdata(json("\xED\xA0\x80")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xED", json::type_error&);
-            // an overlong encoding of '.'
-            CHECK_THROWS_WITH_AS(json::to_bjdata(json("\xC0\xAF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC0", json::type_error&);
-
-            // an object key with ill-formed UTF-8 is rejected the same way
-            CHECK_THROWS_WITH_AS(json::to_bjdata(json{{"\xFF", 1}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-        }
     }
 
     SECTION("Array Type")

tests/src/unit-bson.cpp

@@ -154,51 +154,6 @@ TEST_CASE("BSON")
 #endif
     }
 
-    SECTION("ill-formed UTF-8 (see #5529, #5651)")
-    {
-        // a BSON document {"s": "\xC0\xAE"} (0xC0 0xAE is an overlong
-        // encoding of '.'); the BSON spec does not require a decoder to
-        // reject ill-formed UTF-8 in a string value, so the reader hands the
-        // bytes back unchanged
-        const std::vector<uint8_t> v =
-        {
-            0x0F, 0x00, 0x00, 0x00, // document length
-            0x02, 's', 0x00,        // type 0x02 (string), key "s"
-            0x03, 0x00, 0x00, 0x00, // string length (including null)
-            0xc0, 0xae, 0x00,       // string content and its null terminator
-            0x00                    // document terminator
-        };
-        json j;
-        CHECK_NOTHROW(j = json::from_bson(v));
-        REQUIRE(j.is_object());
-        REQUIRE(j.contains("s"));
-        CHECK(j["s"].get_ref<const json::string_t&>() == std::string("\xc0\xae"));
-        // dump() still requires valid UTF-8 and throws for such a value
-        CHECK_THROWS_AS(j.dump(), json::type_error&);
-        // to_bson() is strict as well, so the value cannot be written back
-        CHECK_THROWS_AS(json::to_bson(j), json::type_error&);
-
-        // to_bson() rejects the same kind of ill-formed string value, before
-        // any bytes reach the output adapter (the BSON document length
-        // prefix must be known up front, so nothing is written incrementally)
-        std::vector<std::uint8_t> out{0x42}; // a sentinel byte the writer must not touch
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"s", "\xFF"}}, nlohmann::detail::output_adapter<std::uint8_t>(out)), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-        CHECK(out == std::vector<std::uint8_t> {0x42});
-
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"s", "\xFF"}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-        // a truncated multi-byte sequence
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"s", "\xC3"}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC3", json::type_error&);
-        // an encoded surrogate half (U+D800)
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"s", "\xED\xA0\x80"}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xED", json::type_error&);
-        // an overlong encoding of '.'
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"s", "\xC0\xAF"}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC0", json::type_error&);
-
-        // an object key with ill-formed UTF-8 is rejected as well; unlike
-        // the reader (which never validates element names), the writer
-        // checks both string values and object keys
-        CHECK_THROWS_WITH_AS(json::to_bson(json{{"\xFF", 1}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-    }
-
     SECTION("lengths exceeding INT32_MAX cannot be serialized to BSON")
     {
         // out_of_range.412 is thrown from a single shared helper

tests/src/unit-cbor.cpp

@@ -1801,40 +1801,19 @@ TEST_CASE("CBOR")
             CHECK_THROWS_WITH_AS(_ = json::from_cbor(std::vector<uint8_t>({0xA1, 0x7C, 0x01})), "[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing CBOR string: expected length specification (0x60-0x7B) or indefinite string type (0x7F); last byte: 0x7C", json::parse_error&);
         }
 
-        SECTION("ill-formed UTF-8 in string (see #5529, #5651)")
+        SECTION("invalid UTF-8 in string (see #5529)")
         {
-            // RFC 8949 §3.1 leaves it up to the decoder whether to reject
-            // ill-formed UTF-8 in a text string; this library does not, and
-            // hands the original bytes back unchanged, matching the
-            // MessagePack reader and the behavior before #5185/#5531 (not in
-            // any release)
-
             // a two-character text string (major type 3) whose bytes are not
-            // valid UTF-8 (0xC0 0xAE is an overlong encoding of '.') round-trips
+            // valid UTF-8 (0xC0 0xAE is an overlong encoding of '.') must be
-            // byte for byte as a string value
+            // rejected at decode time, matching every other kind of
-            const std::vector<uint8_t> ill_formed_value = {0x62, 0xc0, 0xae};
+            // malformed binary input, rather than only failing later when
-            json j_value;
+            // the resulting value is dumped
-            CHECK_NOTHROW(j_value = json::from_cbor(ill_formed_value));
+            json _;
-            REQUIRE(j_value.is_string());
+            CHECK_THROWS_WITH_AS(_ = json::from_cbor(std::vector<uint8_t>({0x62, 0xc0, 0xae})), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing CBOR string: invalid string: ill-formed UTF-8 byte", json::parse_error&);
-            CHECK(j_value.get_ref<const json::string_t&>() == std::string("\xc0\xae"));
+            CHECK(json::from_cbor(std::vector<uint8_t>({0x62, 0xc0, 0xae}), true, false).is_discarded());
-            // dump() still requires valid UTF-8 and throws for such a value,
-            // unless an error handler that replaces or ignores the bytes is
-            // passed
-            CHECK_THROWS_AS(j_value.dump(), json::type_error&);
-            // to_cbor() is strict as well, so the value cannot be written back
-            CHECK_THROWS_AS(json::to_cbor(j_value), json::type_error&);
-
-            // the same bytes as an object key round-trip as well
-            const std::vector<uint8_t> ill_formed_key = {0xa1, 0x62, 0xc0, 0xae, 0x01};
-            json j_key;
-            CHECK_NOTHROW(j_key = json::from_cbor(ill_formed_key));
-            REQUIRE(j_key.is_object());
-            CHECK(j_key.contains(std::string("\xc0\xae")));
-            CHECK_THROWS_AS(json::to_cbor(j_key), json::type_error&);
 
             // a CBOR byte string (major type 2) with the very same bytes is
             // NOT text and must still be accepted as-is
-            json _;
             CHECK_NOTHROW(_ = json::from_cbor(std::vector<uint8_t>({0x42, 0xc0, 0xae})));
             CHECK(_ == json::binary(std::vector<std::uint8_t>({0xc0, 0xae})));
 
@@ -1843,46 +1822,17 @@ TEST_CASE("CBOR")
             CHECK(json::from_cbor(json::to_cbor(j)) == j);
         }
 
-        SECTION("to_cbor rejects ill-formed UTF-8 (see #5651)")
+        SECTION("invalid UTF-8 in indefinite-length string")
-        {
-            // to_cbor() must reject the same ill-formed strings from_cbor()
-            // rejects, so a value it accepts can always be read back
-            CHECK_THROWS_WITH_AS(json::to_cbor(json("\xFF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-            // a truncated multi-byte sequence
-            CHECK_THROWS_WITH_AS(json::to_cbor(json("\xC3")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC3", json::type_error&);
-            // an encoded surrogate half (U+D800)
-            CHECK_THROWS_WITH_AS(json::to_cbor(json("\xED\xA0\x80")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xED", json::type_error&);
-            // an overlong encoding of '.'
-            CHECK_THROWS_WITH_AS(json::to_cbor(json("\xC0\xAF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC0", json::type_error&);
-
-            // an object key with ill-formed UTF-8 is rejected the same way
-            CHECK_THROWS_WITH_AS(json::to_cbor(json{{"\xFF", 1}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-
-            // binary values are not text and are unaffected
-            CHECK_NOTHROW(json::to_cbor(json::binary(std::vector<std::uint8_t>({0xFF}))));
-        }
-
-        SECTION("ill-formed UTF-8 in indefinite-length string")
         {
             json _;
 
-            // the chunks are concatenated as is, without checking that each
+            // every chunk must be valid UTF-8 on its own (RFC 8949, Section
-            // chunk is valid UTF-8 on its own (RFC 8949, Section 3.2.3), so
+            // 3.2.3), so a code point split across two chunks is rejected
-            // a code point split across two chunks yields a valid string
+            CHECK_THROWS_WITH_AS(_ = json::from_cbor(std::vector<uint8_t>({0x7f, 0x61, 0xc3, 0x61, 0xa9, 0xff})), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing CBOR string: invalid string: ill-formed UTF-8 byte", json::parse_error&);
-            CHECK_NOTHROW(_ = json::from_cbor(std::vector<uint8_t>({0x7f, 0x61, 0xc3, 0x61, 0xa9, 0xff})));
+            CHECK(json::from_cbor(std::vector<uint8_t>({0x7f, 0x61, 0xc3, 0x61, 0xa9, 0xff}), true, false).is_discarded());
-            CHECK(_ == "\xc3\xa9");
-            CHECK(_.dump() == "\"\xc3\xa9\"");
 
-            // a truncated code point is kept as is
+            // an ill-formed later chunk is rejected after valid ones
-            CHECK_NOTHROW(_ = json::from_cbor(std::vector<uint8_t>({0x7f, 0x61, 0xc3, 0xff})));
+            CHECK_THROWS_WITH_AS(_ = json::from_cbor(std::vector<uint8_t>({0x7f, 0x62, 0xc3, 0xa9, 0x62, 0xc0, 0xae, 0xff})), "[json.exception.parse_error.113] parse error at byte 7: syntax error while parsing CBOR string: invalid string: ill-formed UTF-8 byte", json::parse_error&);
-            CHECK(_ == "\xc3");
-            CHECK_THROWS_AS(_.dump(), json::type_error&);
-            CHECK_THROWS_AS(json::to_cbor(_), json::type_error&);
-
-            // an ill-formed later chunk is kept after valid ones
-            CHECK_NOTHROW(_ = json::from_cbor(std::vector<uint8_t>({0x7f, 0x62, 0xc3, 0xa9, 0x62, 0xc0, 0xae, 0xff})));
-            CHECK(_ == "\xc3\xa9\xc0\xae");
-            CHECK_THROWS_AS(_.dump(), json::type_error&);
 
             // valid multi-byte chunks are accepted
             CHECK(json::from_cbor(std::vector<uint8_t>({0x7f, 0x62, 0xc3, 0xa9, 0x62, 0xc3, 0xb6, 0xff})) == "\xc3\xa9\xc3\xb6");
@@ -1890,6 +1840,9 @@ TEST_CASE("CBOR")
 
         SECTION("many chunks in indefinite-length string")
         {
+            // only the newly read chunk is validated, not the whole string
+            // collected so far; validating the latter made this input take
+            // quadratic time (about ten seconds for 100000 chunks)
             constexpr std::size_t chunks = 100000;
             std::vector<uint8_t> v{0x7f};
             for (std::size_t i = 0; i < chunks; ++i)

tests/src/unit-diagnostics-optimized.cpp

@@ -0,0 +1,76 @@
+//     __ _____ _____ _____
+//  __|  |   __|     |   | |  JSON for Modern C++ (supporting code)
+// |  |  |__   |  |  | | | |  version 3.12.0
+// |_____|_____|_____|_|___|  https://github.com/nlohmann/json
+//
+// SPDX-FileCopyrightText: 2013-2026 Niels Lohmann <https://nlohmann.me>
+// SPDX-License-Identifier: MIT
+
+// Regression test for https://github.com/nlohmann/json/issues/5742: with
+// JSON_DIAGNOSTICS, GCC (13 to at least 15) reports a false -Warray-bounds
+// error in the inlined set_parents() at -O3. The warning depends on GCC's
+// inlining decisions, so the sections cover patterns that trigger it on
+// different GCC versions (#4819: GCC 13 and 14; #5742: GCC 14 and 15).
+// On GCC, this file is compiled with -O3 -Werror=array-bounds (see
+// tests/CMakeLists.txt), so the test fails to build if the warning returns.
+
+#include "doctest_compatibility.h"
+
+#ifdef JSON_DIAGNOSTICS
+    #undef JSON_DIAGNOSTICS
+#endif
+
+#define JSON_DIAGNOSTICS 1
+
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+
+#include <algorithm>
+#include <iterator>
+#include <utility>
+#include <vector>
+
+namespace
+{
+enum class diag_color
+{
+    red,
+    green,
+    blue
+};
+
+void to_json(json& j, const diag_color& c)
+{
+    static const std::pair<diag_color, json> m[] = // NOLINT(cppcoreguidelines-avoid-c-arrays,hicpp-avoid-c-arrays,modernize-avoid-c-arrays)
+    {
+        {diag_color::red, "r"},
+        {diag_color::green, "g"},
+        {diag_color::blue, "b"},
+    };
+    const auto* it = std::find_if(std::begin(m), std::end(m), [c](const std::pair<diag_color, json>& p)
+    {
+        return p.first == c;
+    });
+    j = it->second;
+}
+} // namespace
+
+TEST_CASE("diagnostics with optimization")
+{
+    SECTION("issue #4819 - object in vector")
+    {
+        std::vector<json> jsons{};
+        jsons.emplace_back(json({{"key", "value"}}));
+        CHECK(jsons.back()["key"] == "value");
+    }
+
+    SECTION("issue #5742 - string values from a static table")
+    {
+        json j = json::array();
+        j.push_back(diag_color::red);
+        j.push_back(diag_color::green);
+        j.push_back(diag_color::blue);
+        CHECK(j.dump() == R"(["r","g","b"])");
+        CHECK_THROWS_WITH_AS(j[1].get<int>(), "[json.exception.type_error.302] (/1) type must be number, but is string", json::type_error);
+    }
+}

tests/src/unit-msgpack.cpp

@@ -1540,39 +1540,19 @@ TEST_CASE("MessagePack")
             CHECK_THROWS_WITH_AS(_ = json::from_msgpack(std::vector<uint8_t>({0x81})), "[json.exception.parse_error.110] parse error at byte 2: syntax error while parsing MessagePack string: unexpected end of input", json::parse_error&);
         }
 
-        SECTION("ill-formed UTF-8 in string (see #5529, #5651)")
+        SECTION("invalid UTF-8 in string (see #5529)")
         {
-            // the MessagePack specification explicitly allows a str object to
-            // contain a byte sequence that is not valid UTF-8 and expects a
-            // deserializer to hand the original bytes back unchanged; this
-            // library follows that, unlike CBOR/UBJSON/BJData/BSON, whose
-            // specifications require text strings to be valid UTF-8
-
             // a fixstr of length 2 (0xA0 | 2) whose bytes are not valid UTF-8
-            // (0xC0 0xAE is an overlong encoding of '.') round-trips byte for
+            // (0xC0 0xAE is an overlong encoding of '.') must be rejected at
-            // byte as a string value
+            // decode time, matching every other kind of malformed binary
-            const std::vector<uint8_t> ill_formed_value = {0xa2, 0xc0, 0xae};
+            // input, rather than only failing later when the resulting
-            json j_value;
+            // value is dumped
-            CHECK_NOTHROW(j_value = json::from_msgpack(ill_formed_value));
+            json _;
-            REQUIRE(j_value.is_string());
+            CHECK_THROWS_WITH_AS(_ = json::from_msgpack(std::vector<uint8_t>({0xa2, 0xc0, 0xae})), "[json.exception.parse_error.113] parse error at byte 3: syntax error while parsing MessagePack string: invalid string: ill-formed UTF-8 byte", json::parse_error&);
-            CHECK(j_value.get_ref<const json::string_t&>() == std::string("\xc0\xae"));
+            CHECK(json::from_msgpack(std::vector<uint8_t>({0xa2, 0xc0, 0xae}), true, false).is_discarded());
-            CHECK(json::from_msgpack(json::to_msgpack(j_value)) == j_value);
-            // dump() still requires valid UTF-8 and throws for such a value,
-            // unless an error handler that replaces or ignores the bytes is
-            // passed
-            CHECK_THROWS_AS(j_value.dump(), json::type_error&);
-
-            // the same bytes as an object key round-trip as well
-            const std::vector<uint8_t> ill_formed_key = {0x81, 0xa2, 0xc0, 0xae, 0x01};
-            json j_key;
-            CHECK_NOTHROW(j_key = json::from_msgpack(ill_formed_key));
-            REQUIRE(j_key.is_object());
-            CHECK(j_key.contains(std::string("\xc0\xae")));
-            CHECK(json::from_msgpack(json::to_msgpack(j_key)) == j_key);
 
             // a MessagePack bin8 blob with the very same bytes is NOT text
             // and must still be accepted as-is
-            json _;
             CHECK_NOTHROW(_ = json::from_msgpack(std::vector<uint8_t>({0xc4, 0x02, 0xc0, 0xae})));
             CHECK(_ == json::binary(std::vector<std::uint8_t>({0xc0, 0xae})));
 

tests/src/unit-ubjson.cpp

@@ -2505,41 +2505,6 @@ TEST_CASE("Universal Binary JSON Specification Examples 1")
             CHECK(json::to_ubjson(j) == v);
             CHECK(json::from_ubjson(v) == j);
         }
-
-        SECTION("ill-formed UTF-8 (see #5529, #5651)")
-        {
-            // none of the binary format specs requires a decoder to reject
-            // ill-formed UTF-8 in a text string, so a value whose bytes are
-            // not valid UTF-8 (0xC0 0xAE is an overlong encoding of '.')
-            // round-trips byte for byte as a string value; to_ubjson() is
-            // strict, so such a value cannot be written back
-            const std::vector<uint8_t> v = {'S', 'i', 2, 0xc0, 0xae};
-            json j;
-            CHECK_NOTHROW(j = json::from_ubjson(v));
-            REQUIRE(j.is_string());
-            CHECK(j.get_ref<const json::string_t&>() == std::string("\xc0\xae"));
-            CHECK_THROWS_AS(j.dump(), json::type_error&);
-            CHECK_THROWS_AS(json::to_ubjson(j), json::type_error&);
-
-            // the same bytes as an object key round-trip as well
-            const std::vector<uint8_t> v_key = {'{', 'i', 2, 0xc0, 0xae, 'i', 1, '}'};
-            json j_key;
-            CHECK_NOTHROW(j_key = json::from_ubjson(v_key));
-            REQUIRE(j_key.is_object());
-            CHECK(j_key.contains(std::string("\xc0\xae")));
-            CHECK_THROWS_AS(json::to_ubjson(j_key), json::type_error&);
-
-            CHECK_THROWS_WITH_AS(json::to_ubjson(json("\xFF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-            // a truncated multi-byte sequence
-            CHECK_THROWS_WITH_AS(json::to_ubjson(json("\xC3")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC3", json::type_error&);
-            // an encoded surrogate half (U+D800)
-            CHECK_THROWS_WITH_AS(json::to_ubjson(json("\xED\xA0\x80")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xED", json::type_error&);
-            // an overlong encoding of '.'
-            CHECK_THROWS_WITH_AS(json::to_ubjson(json("\xC0\xAF")), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xC0", json::type_error&);
-
-            // an object key with ill-formed UTF-8 is rejected the same way
-            CHECK_THROWS_WITH_AS(json::to_ubjson(json{{"\xFF", 1}}), "[json.exception.type_error.316] invalid UTF-8 byte at index 0: 0xFF", json::type_error&);
-        }
     }
 
     SECTION("Array Type")