Keep the MessagePack string test type and its alias in one block

astyle indented the alias oddly when it had an #ifdef of its own after
the binary alias; declare it right after the string type, in the same
block.

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

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

@@ -25,15 +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
-    - `strict`: throw a [`type_error`](../../home/exceptions.md#type-errors) exception in case a decoding error occurs
+    with U+FFFD), and `ignore` (ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the
-      (default),
+    output unchanged, and invalid bytes are dropped)).
-    - `replace`: replace invalid UTF-8 sequences with U+FFFD (� REPLACEMENT CHARACTER),
-    - `ignore`: ignore invalid UTF-8 sequences during serialization; all valid bytes are copied to the output unchanged,
-      and invalid bytes are dropped, and
-    - `keep`: keep invalid UTF-8 sequences during serialization; all bytes are copied to the output unchanged, so the
-      result is not valid UTF-8.
     
 ## Return value
 
@@ -99,4 +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 value `keep` added in version 3.13.0.

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

@@ -4,13 +4,12 @@
 enum class error_handler_t {
     strict,
     replace,
-    ignore,
+    ignore
-    keep
 };
 ```
 
 This enumeration is used in the [`dump`](dump.md) function to choose how to treat decoding errors while serializing a
-`basic_json` value. Four values are differentiated:
+`basic_json` value. Three values are differentiated:
 
 strict
 :   throw a `type_error` exception in case of invalid UTF-8
@@ -21,12 +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; all bytes are copied to the output unchanged. Valid characters are still escaped as
-    usual (e.g., `"`, `\\`, and control characters), so the result has valid JSON syntax, but it is not valid UTF-8.
-    In particular, [`parse`](parse.md) rejects it, and with `ensure_ascii` set to `true`, the invalid bytes are the
-    only non-ASCII bytes of the output.
-
 ## Examples
 
 ??? example
@@ -47,4 +40,3 @@ keep
 ## Version history
 
 - Added in version 3.4.0.
-- Added value `keep` in version 3.13.0.

docs/mkdocs/docs/api/basic_json/to_msgpack.md

@@ -34,6 +34,15 @@ 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 [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412) if the length of a string, binary
+  value, array, or object exceeds 4294967295, the maximum MessagePack can store; example:
+  `"MessagePack length 4294967296 exceeds maximum of 4294967295"`
+- Throws [`out_of_range.415`](../../home/exceptions.md#jsonexceptionout_of_range415) if the subtype of a binary value
+  exceeds 255, the maximum of the MessagePack ext type; example:
+  `"subtype 70000 is too large for the MessagePack ext type (max 255)"`
+
 ## Complexity
 
 Linear in the size of the JSON value `j`.
@@ -65,3 +74,4 @@ Linear in the size of the JSON value `j`.
 ## Version history
 
 - Added in version 2.0.9.
+- Throws `out_of_range.412` and `out_of_range.415` since version 3.13.0.

docs/mkdocs/docs/examples/error_handler_t.cpp

@@ -1,4 +1,3 @@
-#include <iomanip>
 #include <iostream>
 #include <nlohmann/json.hpp>
 
@@ -22,12 +21,4 @@ int main()
               << "\nstring with ignored invalid characters: "
               << j_invalid.dump(-1, ' ', false, json::error_handler_t::ignore)
               << '\n';
-
-    // the invalid byte is kept; print the result byte-wise to make it visible
-    std::cout << "string with kept invalid characters:";
-    for (const unsigned char c : j_invalid.dump(-1, ' ', false, json::error_handler_t::keep))
-    {
-        std::cout << ' ' << std::hex << std::setw(2) << std::setfill('0') << static_cast<int>(c);
-    }
-    std::cout << '\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 kept invalid characters: 22 c3 a4 a9 c3 bc 22

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

@@ -65,6 +65,8 @@ specification:
       - arrays with more than 4294967295 elements
       - objects with more than 4294967295 elements
 
+    Serializing such a value throws [`out_of_range.412`](../../home/exceptions.md#jsonexceptionout_of_range412).
+
 !!! info "NaN/infinity handling"
 
     `NaN`, `Infinity`, and `-Infinity` are serialized as a MessagePack float 32 (type 0xCA, 5 bytes total),

docs/mkdocs/docs/features/serialization.md

@@ -64,7 +64,6 @@ serialization fails by default. The fourth argument of `dump` selects an
 - `strict` (default) — throw a [`type_error.316`](../home/exceptions.md#jsonexceptiontype_error316) exception.
 - `replace` — replace invalid bytes with the Unicode replacement character U+FFFD (`�`).
 - `ignore` — silently drop invalid bytes.
-- `keep` — copy invalid bytes to the output unchanged; the result is not valid UTF-8.
 
 ??? example
 

docs/mkdocs/docs/home/exceptions.md

@@ -755,7 +755,6 @@ The `dump()` function only works with UTF-8 encoded strings; that is, if you ass
     - Pass an error handler as last parameter to the `dump()` function to avoid this exception:
         - `json::error_handler_t::replace` will replace invalid bytes sequences with `U+FFFD` 
         - `json::error_handler_t::ignore` will silently ignore invalid byte sequences
-        - `json::error_handler_t::keep` will copy invalid byte sequences to the output unchanged
 
 ### json.exception.type_error.317
 
@@ -933,19 +932,25 @@ A JSON Patch `add` operation cannot be applied because the target location's par
 
 ### json.exception.out_of_range.412
 
-BSON stores the length of documents, arrays, strings, and binary values in a signed 32-bit integer. This exception is thrown when a value is too large to be described by such a length field.
+BSON stores the length of documents, arrays, strings, and binary values in a signed 32-bit integer, and MessagePack
+stores the length of strings, binary values, arrays, and objects in at most an unsigned 32-bit integer. This exception
+is thrown when a value is too large to be described by such a length field.
 
-!!! failure "Example message"
+!!! failure "Example messages"
 
     ```
     BSON length 2147483661 exceeds maximum of 2147483647
     ```
+    ```
+    MessagePack length 4294967296 exceeds maximum of 4294967295
+    ```
 
 !!! note
 
-    This exception was added in version 3.13.0. Before that, the length was silently truncated, and
+    This exception was added in version 3.13.0. Before that, the BSON length was silently truncated, and
     [`to_bson`](../api/basic_json/to_bson.md) produced documents with negative length prefixes that
-    [`from_bson`](../api/basic_json/from_bson.md) rejected.
+    [`from_bson`](../api/basic_json/from_bson.md) rejected; [`to_msgpack`](../api/basic_json/to_msgpack.md) wrote such
+    a value without any length, producing output that could not be read back.
 
 ### json.exception.out_of_range.413
 

docs/mkdocs/docs/home/faq.md

@@ -85,7 +85,7 @@ The library supports **Unicode input** as follows:
 - The library will not replace [Unicode noncharacters](http://www.unicode.org/faq/private_use.html#nonchar1).
 - Invalid surrogates (e.g., incomplete pairs such as `\uDEAD`) will yield parse errors.
 - The strings stored in the library are UTF-8 encoded. When using the default string type (`std::string`), note that its length/size functions return the number of stored bytes rather than the number of characters or glyphs.
-- When you store strings with different encodings in the library, calling [`dump()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a50ec80b02d0f3f51130d4abb5d1cfdc5.html#a50ec80b02d0f3f51130d4abb5d1cfdc5) may throw an exception unless `json::error_handler_t::replace`, `json::error_handler_t::ignore`, or `json::error_handler_t::keep` are used as error handlers.
+- When you store strings with different encodings in the library, calling [`dump()`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a50ec80b02d0f3f51130d4abb5d1cfdc5.html#a50ec80b02d0f3f51130d4abb5d1cfdc5) may throw an exception unless `json::error_handler_t::replace` or `json::error_handler_t::ignore` are used as error handlers.
 
 In most cases, the parser is right to complain, because the input is not UTF-8 encoded. This is especially true for Microsoft Windows, where Latin-1 or ISO 8859-1 is often the standard encoding.
 

include/nlohmann/detail/output/binary_writer.hpp

@@ -466,6 +466,23 @@ class binary_writer
         }
     }
 
+    /*!
+    @brief check that @a length fits into the 32 bits that MessagePack stores
+           the length of a string, binary value, array, or object in
+    @return the length as an unsigned 32-bit integer
+    @throw out_of_range.412 if @a length exceeds the range of std::uint32_t
+    */
+    static std::uint32_t to_msgpack_length(const std::size_t length, const BasicJsonType& j)
+    {
+        if (JSON_HEDLEY_UNLIKELY(!value_in_range_of<std::uint32_t>(length)))
+        {
+            JSON_THROW(out_of_range::create(412, concat("MessagePack length ", std::to_string(length), " exceeds maximum of ", std::to_string((std::numeric_limits<std::uint32_t>::max)())), &j));
+        }
+
+        static_cast<void>(j);
+        return static_cast<std::uint32_t>(length);
+    }
+
     /*!
     @param[in] j  JSON value to serialize
     */
@@ -606,7 +623,7 @@ class binary_writer
             case value_t::string:
             {
                 // step 1: write control byte and the string length
-                const auto N = j.m_data.m_value.string->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.string->size(), j);
                 if (N <= 31)
                 {
                     // fixstr
@@ -624,7 +641,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDA));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // str 32
                     oa.write_character(to_char_type(0xDB));
@@ -641,7 +658,7 @@ class binary_writer
             case value_t::array:
             {
                 // step 1: write control byte and the array size
-                const auto N = j.m_data.m_value.array->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.array->size(), j);
                 if (N <= 15)
                 {
                     // fixarray
@@ -653,7 +670,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDC));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // array 32
                     oa.write_character(to_char_type(0xDD));
@@ -675,7 +692,7 @@ class binary_writer
                 const bool use_ext = j.m_data.m_value.binary->has_subtype();
 
                 // step 1: write control byte and the byte string length
-                const auto N = j.m_data.m_value.binary->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.binary->size(), j);
                 if (N <= (std::numeric_limits<std::uint8_t>::max)())
                 {
                     std::uint8_t output_type{};
@@ -727,7 +744,7 @@ class binary_writer
                     oa.write_character(to_char_type(output_type));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     const std::uint8_t output_type = use_ext
                                                      ? 0xC9 // ext 32
@@ -759,7 +776,7 @@ class binary_writer
             case value_t::object:
             {
                 // step 1: write control byte and the object size
-                const auto N = j.m_data.m_value.object->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.object->size(), j);
                 if (N <= 15)
                 {
                     // fixmap
@@ -771,7 +788,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDE));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // map 32
                     oa.write_character(to_char_type(0xDF));

include/nlohmann/detail/output/serializer.hpp

@@ -48,8 +48,7 @@ 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
+    ignore   ///< ignore invalid UTF-8 sequences
-    keep     ///< keep invalid UTF-8 sequences; their bytes are copied unchanged
 };
 
 template<typename BasicJsonType>
@@ -1020,47 +1019,6 @@ class serializer
                             break;
                         }
 
-                        case error_handler_t::keep:
-                        {
-                            // drop whatever the incomplete sequence left in
-                            // the buffer (only copied if !EnsureAscii) and copy
-                            // the ill-formed bytes from the input instead
-                            bytes = bytes_after_last_accept;
-
-                            if (undumped_chars > 0)
-                            {
-                                // the pending bytes of the incomplete sequence
-                                // are ill-formed; the current byte may be OK for
-                                // itself, so we would like to read it again
-                                for (std::size_t j = i - undumped_chars; j < i; ++j)
-                                {
-                                    string_buffer[bytes++] = s[j];
-                                }
-                                --i;
-                            }
-                            else
-                            {
-                                // the current byte cannot start any sequence
-                                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
                     }
@@ -1106,15 +1064,6 @@ class serializer
                     break;
                 }
 
-                case error_handler_t::keep:
-                {
-                    // write all accepted bytes
-                    put_buffer(string_buffer, bytes_after_last_accept);
-                    // copy the bytes of the incomplete sequence unchanged
-                    put_string(s, s.size() - undumped_chars, s.size());
-                    break;
-                }
-
                 case error_handler_t::replace:
                 {
                     // write all accepted bytes

single_include/nlohmann/json.hpp

@@ -19931,6 +19931,23 @@ class binary_writer
         }
     }
 
+    /*!
+    @brief check that @a length fits into the 32 bits that MessagePack stores
+           the length of a string, binary value, array, or object in
+    @return the length as an unsigned 32-bit integer
+    @throw out_of_range.412 if @a length exceeds the range of std::uint32_t
+    */
+    static std::uint32_t to_msgpack_length(const std::size_t length, const BasicJsonType& j)
+    {
+        if (JSON_HEDLEY_UNLIKELY(!value_in_range_of<std::uint32_t>(length)))
+        {
+            JSON_THROW(out_of_range::create(412, concat("MessagePack length ", std::to_string(length), " exceeds maximum of ", std::to_string((std::numeric_limits<std::uint32_t>::max)())), &j));
+        }
+
+        static_cast<void>(j);
+        return static_cast<std::uint32_t>(length);
+    }
+
     /*!
     @param[in] j  JSON value to serialize
     */
@@ -20071,7 +20088,7 @@ class binary_writer
             case value_t::string:
             {
                 // step 1: write control byte and the string length
-                const auto N = j.m_data.m_value.string->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.string->size(), j);
                 if (N <= 31)
                 {
                     // fixstr
@@ -20089,7 +20106,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDA));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // str 32
                     oa.write_character(to_char_type(0xDB));
@@ -20106,7 +20123,7 @@ class binary_writer
             case value_t::array:
             {
                 // step 1: write control byte and the array size
-                const auto N = j.m_data.m_value.array->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.array->size(), j);
                 if (N <= 15)
                 {
                     // fixarray
@@ -20118,7 +20135,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDC));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // array 32
                     oa.write_character(to_char_type(0xDD));
@@ -20140,7 +20157,7 @@ class binary_writer
                 const bool use_ext = j.m_data.m_value.binary->has_subtype();
 
                 // step 1: write control byte and the byte string length
-                const auto N = j.m_data.m_value.binary->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.binary->size(), j);
                 if (N <= (std::numeric_limits<std::uint8_t>::max)())
                 {
                     std::uint8_t output_type{};
@@ -20192,7 +20209,7 @@ class binary_writer
                     oa.write_character(to_char_type(output_type));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     const std::uint8_t output_type = use_ext
                                                      ? 0xC9 // ext 32
@@ -20224,7 +20241,7 @@ class binary_writer
             case value_t::object:
             {
                 // step 1: write control byte and the object size
-                const auto N = j.m_data.m_value.object->size();
+                const auto N = to_msgpack_length(j.m_data.m_value.object->size(), j);
                 if (N <= 15)
                 {
                     // fixmap
@@ -20236,7 +20253,7 @@ class binary_writer
                     oa.write_character(to_char_type(0xDE));
                     write_number(static_cast<std::uint16_t>(N));
                 }
-                else if (N <= (std::numeric_limits<std::uint32_t>::max)())
+                else
                 {
                     // map 32
                     oa.write_character(to_char_type(0xDF));
@@ -23006,8 +23023,7 @@ 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
+    ignore   ///< ignore invalid UTF-8 sequences
-    keep     ///< keep invalid UTF-8 sequences; their bytes are copied unchanged
 };
 
 template<typename BasicJsonType>
@@ -23978,47 +23994,6 @@ class serializer
                             break;
                         }
 
-                        case error_handler_t::keep:
-                        {
-                            // drop whatever the incomplete sequence left in
-                            // the buffer (only copied if !EnsureAscii) and copy
-                            // the ill-formed bytes from the input instead
-                            bytes = bytes_after_last_accept;
-
-                            if (undumped_chars > 0)
-                            {
-                                // the pending bytes of the incomplete sequence
-                                // are ill-formed; the current byte may be OK for
-                                // itself, so we would like to read it again
-                                for (std::size_t j = i - undumped_chars; j < i; ++j)
-                                {
-                                    string_buffer[bytes++] = s[j];
-                                }
-                                --i;
-                            }
-                            else
-                            {
-                                // the current byte cannot start any sequence
-                                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
                     }
@@ -24064,15 +24039,6 @@ class serializer
                     break;
                 }
 
-                case error_handler_t::keep:
-                {
-                    // write all accepted bytes
-                    put_buffer(string_buffer, bytes_after_last_accept);
-                    // copy the bytes of the incomplete sequence unchanged
-                    put_string(s, s.size() - undumped_chars, s.size());
-                    break;
-                }
-
                 case error_handler_t::replace:
                 {
                     // write all accepted bytes

tests/src/unit-msgpack.cpp

@@ -14,6 +14,7 @@ using nlohmann::json;
     using namespace nlohmann::literals; // NOLINT(google-build-using-namespace)
 #endif
 
+#include <cstdint> // SIZE_MAX, UINT32_MAX
 #include <fstream>
 #include <sstream>
 #include <iomanip>
@@ -2150,3 +2151,79 @@ TEST_CASE("MessagePack with std::byte")
     }
 }
 #endif
+
+namespace
+{
+// types that report a size beyond UINT32_MAX without allocating that much
+// memory, so the MessagePack length limit can be tested cheaply; see the
+// similar types in unit-bson.cpp
+std::size_t beyond_uint32_size()
+{
+    return static_cast<std::size_t>((std::numeric_limits<std::uint32_t>::max)()) + 1;
+}
+
+class beyond_uint32_binary_t : public std::vector<std::uint8_t>
+{
+  public:
+    using std::vector<std::uint8_t>::vector;
+
+    size_type size() const noexcept // NOLINT(readability-convert-member-functions-to-static)
+    {
+        return beyond_uint32_size();
+    }
+};
+
+// with clang and libstdc++ 10, the std::filesystem::path conversion that
+// C++17 builds consider for every string type is ambiguous for a class
+// derived from std::string, so the string case is not tested there
+#if !(defined(__clang__) && defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE < 11)
+    #define JSON_TEST_BEYOND_UINT32_STRING 1
+#endif
+
+#ifdef JSON_TEST_BEYOND_UINT32_STRING
+class beyond_uint32_string_t : public std::string
+{
+  public:
+    using std::string::string;
+
+    size_type size() const noexcept // NOLINT(readability-convert-member-functions-to-static)
+    {
+        return beyond_uint32_size();
+    }
+};
+
+using beyond_uint32_string_json = nlohmann::basic_json <
+                                  std::map, std::vector, beyond_uint32_string_t, bool, std::int64_t, std::uint64_t,
+                                  double, std::allocator, nlohmann::adl_serializer, std::vector<std::uint8_t>, void >;
+#endif
+
+using beyond_uint32_binary_json = nlohmann::basic_json <
+                                  std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t,
+                                  double, std::allocator, nlohmann::adl_serializer, beyond_uint32_binary_t, void >;
+} // namespace
+
+TEST_CASE("MessagePack lengths beyond UINT32_MAX cannot be serialized")
+{
+    // MessagePack stores the length of a string, binary value, array, or
+    // object in at most 32 bits; a larger one used to be written without any
+    // length at all
+#if SIZE_MAX > UINT32_MAX
+    {
+        const char* const expected = "[json.exception.out_of_range.412] MessagePack length 4294967296 exceeds maximum of 4294967295";
+
+        const beyond_uint32_binary_json binary = beyond_uint32_binary_json::binary(beyond_uint32_binary_t{});
+        CHECK_THROWS_WITH_AS(beyond_uint32_binary_json::to_msgpack(binary), expected, beyond_uint32_binary_json::out_of_range&);
+
+        const beyond_uint32_binary_json ext = beyond_uint32_binary_json::binary(beyond_uint32_binary_t{}, 42);
+        CHECK_THROWS_WITH_AS(beyond_uint32_binary_json::to_msgpack(ext), expected, beyond_uint32_binary_json::out_of_range&);
+
+#ifdef JSON_TEST_BEYOND_UINT32_STRING
+        // created from its type rather than from a beyond_uint32_string_t:
+        // that would consider the std::filesystem::path conversion, which
+        // libstdc++ 10 cannot decide for a class derived from std::string
+        const beyond_uint32_string_json string(beyond_uint32_string_json::value_t::string);
+        CHECK_THROWS_WITH_AS(beyond_uint32_string_json::to_msgpack(string), expected, beyond_uint32_string_json::out_of_range&);
+#endif
+    }
+#endif
+}

tests/src/unit-regression2.cpp

@@ -765,15 +765,6 @@ TEST_CASE("regression tests 2")
         CHECK(j == k);
     }
 
-    SECTION("issue #4552 - UTF-8 invalid characters are not always ignored when dumping with error_handler_t::ignore")
-    {
-        json node;
-        node["test"] = "test\334\005";
-        CHECK(node.dump(-1, ' ', false, json::error_handler_t::ignore) == "{\"test\":\"test\\u0005\"}");
-        CHECK(node.dump(-1, ' ', false, json::error_handler_t::keep) == "{\"test\":\"test\334\\u0005\"}");
-        CHECK(node.dump(-1, ' ', true, json::error_handler_t::keep) == "{\"test\":\"test\334\\u0005\"}");
-    }
-
 }
 
 TEST_CASE("regression test - parser callback must not lose a duplicate key's prior value")

tests/src/unit-serialization.cpp

@@ -92,8 +92,6 @@ TEST_CASE("serialization")
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::ignore) == "\"äü\"");
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::replace) == "\"ä\xEF\xBF\xBDü\"");
             CHECK(j.dump(-1, ' ', true, json::error_handler_t::replace) == "\"\\u00e4\\ufffd\\u00fc\"");
-            CHECK(j.dump(-1, ' ', false, json::error_handler_t::keep) == "\"ä\xA9ü\"");
-            CHECK(j.dump(-1, ' ', true, json::error_handler_t::keep) == "\"\\u00e4\xA9\\u00fc\"");
         }
 
         SECTION("invalid character (regression guard for shared UTF-8 decoder, see #5529)")
@@ -116,8 +114,6 @@ TEST_CASE("serialization")
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::ignore) == "\"123\"");
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::replace) == "\"123\xEF\xBF\xBD\"");
             CHECK(j.dump(-1, ' ', true, json::error_handler_t::replace) == "\"123\\ufffd\"");
-            CHECK(j.dump(-1, ' ', false, json::error_handler_t::keep) == "\"123\xC2\"");
-            CHECK(j.dump(-1, ' ', true, json::error_handler_t::keep) == "\"123\xC2\"");
         }
 
         SECTION("unexpected character")
@@ -130,39 +126,6 @@ TEST_CASE("serialization")
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::ignore) == "\"123456\"");
             CHECK(j.dump(-1, ' ', false, json::error_handler_t::replace) == "\"123\xEF\xBF\xBD\x34\x35\x36\"");
             CHECK(j.dump(-1, ' ', true, json::error_handler_t::replace) == "\"123\\ufffd456\"");
-            CHECK(j.dump(-1, ' ', false, json::error_handler_t::keep) == "\"123\xF1\xB0\x34\x35\x36\"");
-            CHECK(j.dump(-1, ' ', true, json::error_handler_t::keep) == "\"123\xF1\xB0\x34\x35\x36\"");
-        }
-
-        SECTION("keep: valid characters are still escaped")
-        {
-            // an invalid byte followed by characters that must be escaped
-            const json j = "\xC2\"\\\n\xFF\x05";
-            CHECK(j.dump(-1, ' ', false, json::error_handler_t::keep) == "\"\xC2\\\"\\\\\\n\xFF\\u0005\"");
-            CHECK(j.dump(-1, ' ', true, json::error_handler_t::keep) == "\"\xC2\\\"\\\\\\n\xFF\\u0005\"");
-        }
-
-        SECTION("keep: truncated multibyte sequences")
-        {
-            CHECK(json("\xF0\x9F\x98").dump(-1, ' ', false, json::error_handler_t::keep) == "\"\xF0\x9F\x98\"");
-            CHECK(json("\xF0\x9F\x98").dump(-1, ' ', true, json::error_handler_t::keep) == "\"\xF0\x9F\x98\"");
-            CHECK(json("\xF0\x9F\x98" "a").dump(-1, ' ', false, json::error_handler_t::keep) == "\"\xF0\x9F\x98" "a\"");
-            CHECK(json("\xF0\x9F\x98" "a").dump(-1, ' ', true, json::error_handler_t::keep) == "\"\xF0\x9F\x98" "a\"");
-        }
-
-        SECTION("keep: long string with many invalid bytes")
-        {
-            // exceeds the internal string buffer several times
-            std::string input;
-            std::string expected = "\"";
-            for (int i = 0; i < 2000; ++i)
-            {
-                input += "\xFF\xE2\x82\n\xC3\xA4";
-                expected += "\xFF\xE2\x82\\n\xC3\xA4";
-            }
-            expected += "\"";
-            const json j = input;
-            CHECK(j.dump(-1, ' ', false, json::error_handler_t::keep) == expected);
         }
 
         SECTION("U+FFFD Substitution of Maximal Subparts")

tests/src/unit-unicode2.cpp

@@ -14,7 +14,6 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <algorithm>
 #include <fstream>
 #include <sstream>
 #include <iostream>
@@ -76,11 +75,8 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     static std::string s_replaced2;
     static std::string s_replaced_ascii;
     static std::string s_replaced2_ascii;
-    static std::string s_kept;
-    static std::string s_kept2;
-    static std::string s_kept_ascii;
 
-    // dumping with ignore/replace/keep must not throw in any case
+    // dumping with ignore/replace must not throw in any case
     s_ignored = j.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored2 = j2.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored_ascii = j.dump(-1, ' ', true, json::error_handler_t::ignore);
@@ -89,9 +85,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     s_replaced2 = j2.dump(-1, ' ', false, json::error_handler_t::replace);
     s_replaced_ascii = j.dump(-1, ' ', true, json::error_handler_t::replace);
     s_replaced2_ascii = j2.dump(-1, ' ', true, json::error_handler_t::replace);
-    s_kept = j.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept2 = j2.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept_ascii = j.dump(-1, ' ', true, json::error_handler_t::keep);
 
     if (success_expected)
     {
@@ -101,7 +94,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
         // all dumps should agree on the string
         CHECK(s_strict == s_ignored);
         CHECK(s_strict == s_replaced);
-        CHECK(s_strict == s_kept);
     }
     else
     {
@@ -113,20 +105,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
 
         // check that replace string contains a replacement character
         CHECK(s_replaced.find("\xEF\xBF\xBD") != std::string::npos);
-
-        // ignore drops the invalid bytes, keep copies them
-        CHECK(s_ignored != s_kept);
-        CHECK(s_ignored_ascii != s_kept_ascii);
-
-        // unless a byte needs escaping, keep copies the input unchanged
-        const bool needs_escaping = std::any_of(json_string.begin(), json_string.end(), [](char c)
-        {
-            return static_cast<unsigned char>(c) < 0x20 || c == '"' || c == '\\';
-        });
-        if (!needs_escaping)
-        {
-            CHECK(s_kept == "\"" + json_string + "\"");
-        }
     }
 
     // check that prefix and suffix are preserved
@@ -138,8 +116,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     CHECK(s_replaced2.substr(s_replaced2.size() - 4, 3) == "xyz");
     CHECK(s_replaced2_ascii.substr(1, 3) == "abc");
     CHECK(s_replaced2_ascii.substr(s_replaced2_ascii.size() - 4, 3) == "xyz");
-    CHECK(s_kept2.substr(1, 3) == "abc");
-    CHECK(s_kept2.substr(s_kept2.size() - 4, 3) == "xyz");
 }
 
 void check_utf8string(bool success_expected, int byte1, int byte2, int byte3, int byte4);

tests/src/unit-unicode3.cpp

@@ -14,7 +14,6 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <algorithm>
 #include <fstream>
 #include <sstream>
 #include <iostream>
@@ -76,11 +75,8 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     static std::string s_replaced2;
     static std::string s_replaced_ascii;
     static std::string s_replaced2_ascii;
-    static std::string s_kept;
-    static std::string s_kept2;
-    static std::string s_kept_ascii;
 
-    // dumping with ignore/replace/keep must not throw in any case
+    // dumping with ignore/replace must not throw in any case
     s_ignored = j.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored2 = j2.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored_ascii = j.dump(-1, ' ', true, json::error_handler_t::ignore);
@@ -89,9 +85,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     s_replaced2 = j2.dump(-1, ' ', false, json::error_handler_t::replace);
     s_replaced_ascii = j.dump(-1, ' ', true, json::error_handler_t::replace);
     s_replaced2_ascii = j2.dump(-1, ' ', true, json::error_handler_t::replace);
-    s_kept = j.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept2 = j2.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept_ascii = j.dump(-1, ' ', true, json::error_handler_t::keep);
 
     if (success_expected)
     {
@@ -101,7 +94,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
         // all dumps should agree on the string
         CHECK(s_strict == s_ignored);
         CHECK(s_strict == s_replaced);
-        CHECK(s_strict == s_kept);
     }
     else
     {
@@ -113,20 +105,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
 
         // check that replace string contains a replacement character
         CHECK(s_replaced.find("\xEF\xBF\xBD") != std::string::npos);
-
-        // ignore drops the invalid bytes, keep copies them
-        CHECK(s_ignored != s_kept);
-        CHECK(s_ignored_ascii != s_kept_ascii);
-
-        // unless a byte needs escaping, keep copies the input unchanged
-        const bool needs_escaping = std::any_of(json_string.begin(), json_string.end(), [](char c)
-        {
-            return static_cast<unsigned char>(c) < 0x20 || c == '"' || c == '\\';
-        });
-        if (!needs_escaping)
-        {
-            CHECK(s_kept == "\"" + json_string + "\"");
-        }
     }
 
     // check that prefix and suffix are preserved
@@ -138,8 +116,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     CHECK(s_replaced2.substr(s_replaced2.size() - 4, 3) == "xyz");
     CHECK(s_replaced2_ascii.substr(1, 3) == "abc");
     CHECK(s_replaced2_ascii.substr(s_replaced2_ascii.size() - 4, 3) == "xyz");
-    CHECK(s_kept2.substr(1, 3) == "abc");
-    CHECK(s_kept2.substr(s_kept2.size() - 4, 3) == "xyz");
 }
 
 void check_utf8string(bool success_expected, int byte1, int byte2, int byte3, int byte4);

tests/src/unit-unicode4.cpp

@@ -14,7 +14,6 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <algorithm>
 #include <fstream>
 #include <sstream>
 #include <iostream>
@@ -76,11 +75,8 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     static std::string s_replaced2;
     static std::string s_replaced_ascii;
     static std::string s_replaced2_ascii;
-    static std::string s_kept;
-    static std::string s_kept2;
-    static std::string s_kept_ascii;
 
-    // dumping with ignore/replace/keep must not throw in any case
+    // dumping with ignore/replace must not throw in any case
     s_ignored = j.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored2 = j2.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored_ascii = j.dump(-1, ' ', true, json::error_handler_t::ignore);
@@ -89,9 +85,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     s_replaced2 = j2.dump(-1, ' ', false, json::error_handler_t::replace);
     s_replaced_ascii = j.dump(-1, ' ', true, json::error_handler_t::replace);
     s_replaced2_ascii = j2.dump(-1, ' ', true, json::error_handler_t::replace);
-    s_kept = j.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept2 = j2.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept_ascii = j.dump(-1, ' ', true, json::error_handler_t::keep);
 
     if (success_expected)
     {
@@ -101,7 +94,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
         // all dumps should agree on the string
         CHECK(s_strict == s_ignored);
         CHECK(s_strict == s_replaced);
-        CHECK(s_strict == s_kept);
     }
     else
     {
@@ -113,20 +105,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
 
         // check that replace string contains a replacement character
         CHECK(s_replaced.find("\xEF\xBF\xBD") != std::string::npos);
-
-        // ignore drops the invalid bytes, keep copies them
-        CHECK(s_ignored != s_kept);
-        CHECK(s_ignored_ascii != s_kept_ascii);
-
-        // unless a byte needs escaping, keep copies the input unchanged
-        const bool needs_escaping = std::any_of(json_string.begin(), json_string.end(), [](char c)
-        {
-            return static_cast<unsigned char>(c) < 0x20 || c == '"' || c == '\\';
-        });
-        if (!needs_escaping)
-        {
-            CHECK(s_kept == "\"" + json_string + "\"");
-        }
     }
 
     // check that prefix and suffix are preserved
@@ -138,8 +116,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     CHECK(s_replaced2.substr(s_replaced2.size() - 4, 3) == "xyz");
     CHECK(s_replaced2_ascii.substr(1, 3) == "abc");
     CHECK(s_replaced2_ascii.substr(s_replaced2_ascii.size() - 4, 3) == "xyz");
-    CHECK(s_kept2.substr(1, 3) == "abc");
-    CHECK(s_kept2.substr(s_kept2.size() - 4, 3) == "xyz");
 }
 
 void check_utf8string(bool success_expected, int byte1, int byte2, int byte3, int byte4);

tests/src/unit-unicode5.cpp

@@ -14,7 +14,6 @@
 #include <nlohmann/json.hpp>
 using nlohmann::json;
 
-#include <algorithm>
 #include <fstream>
 #include <sstream>
 #include <iostream>
@@ -76,11 +75,8 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     static std::string s_replaced2;
     static std::string s_replaced_ascii;
     static std::string s_replaced2_ascii;
-    static std::string s_kept;
-    static std::string s_kept2;
-    static std::string s_kept_ascii;
 
-    // dumping with ignore/replace/keep must not throw in any case
+    // dumping with ignore/replace must not throw in any case
     s_ignored = j.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored2 = j2.dump(-1, ' ', false, json::error_handler_t::ignore);
     s_ignored_ascii = j.dump(-1, ' ', true, json::error_handler_t::ignore);
@@ -89,9 +85,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     s_replaced2 = j2.dump(-1, ' ', false, json::error_handler_t::replace);
     s_replaced_ascii = j.dump(-1, ' ', true, json::error_handler_t::replace);
     s_replaced2_ascii = j2.dump(-1, ' ', true, json::error_handler_t::replace);
-    s_kept = j.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept2 = j2.dump(-1, ' ', false, json::error_handler_t::keep);
-    s_kept_ascii = j.dump(-1, ' ', true, json::error_handler_t::keep);
 
     if (success_expected)
     {
@@ -101,7 +94,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
         // all dumps should agree on the string
         CHECK(s_strict == s_ignored);
         CHECK(s_strict == s_replaced);
-        CHECK(s_strict == s_kept);
     }
     else
     {
@@ -113,20 +105,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
 
         // check that replace string contains a replacement character
         CHECK(s_replaced.find("\xEF\xBF\xBD") != std::string::npos);
-
-        // ignore drops the invalid bytes, keep copies them
-        CHECK(s_ignored != s_kept);
-        CHECK(s_ignored_ascii != s_kept_ascii);
-
-        // unless a byte needs escaping, keep copies the input unchanged
-        const bool needs_escaping = std::any_of(json_string.begin(), json_string.end(), [](char c)
-        {
-            return static_cast<unsigned char>(c) < 0x20 || c == '"' || c == '\\';
-        });
-        if (!needs_escaping)
-        {
-            CHECK(s_kept == "\"" + json_string + "\"");
-        }
     }
 
     // check that prefix and suffix are preserved
@@ -138,8 +116,6 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
     CHECK(s_replaced2.substr(s_replaced2.size() - 4, 3) == "xyz");
     CHECK(s_replaced2_ascii.substr(1, 3) == "abc");
     CHECK(s_replaced2_ascii.substr(s_replaced2_ascii.size() - 4, 3) == "xyz");
-    CHECK(s_kept2.substr(1, 3) == "abc");
-    CHECK(s_kept2.substr(s_kept2.size() - 4, 3) == "xyz");
 }
 
 void check_utf8string(bool success_expected, int byte1, int byte2, int byte3, int byte4);