json_sax_dom_callback_parser::key() unconditionally overwrote the object
slot for a key with a `discarded` placeholder as soon as the key was
accepted by the parser callback. For a duplicate key (legal JSON), this
destroyed the pre-existing value from an earlier occurrence of the same
key before the new value was even parsed. If the new value was then
rejected by the callback, remove_discarded_value() erased the member
entirely instead of leaving the original value in place, contradicting
the documented behavior that a discarded value behaves as if it was
never read.
Add a small stash of (slot pointer, previous value) pairs so that when
key() overwrites an existing member with the discarded placeholder, the
previous value can be restored later if the corresponding value (scalar,
object, or array) is rejected, instead of being erased. The stash entry
is dropped without restoring once the new value is definitively
accepted (in handle_value() for scalars, end_object()/end_array() for
containers), so a duplicate key whose new value is accepted still keeps
the last value as before. Non-duplicate keys are unaffected: rejecting
their value still removes the member entirely, since there is nothing
to restore.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
The diagnostic position of a string value was derived by subtracting the
parsed value's length from the end position. Escape sequences make the
source token longer than the value it parses to, so the reported start
position landed inside the string, one byte off per escape sequence:
input: {"a":"\n\n\n\n\n\n"}
start_pos() == 11, so the reported range covered n\n\n\n"
instead of the documented "\n\n\n\n\n\n"
This contradicts the documented behavior of start_pos(), which is the
position of the opening quote, and it also corrupted the "(bytes N-M)"
part of JSON_DIAGNOSTICS exception messages. Strings with multi-byte
UTF-8 but no escapes were unaffected, which is why this went unnoticed.
Record the offset of the token in the lexer when it starts scanning and
use that, instead of reconstructing it from the parsed value. Booleans,
null and numbers already reported correct positions and are unchanged.
The new lexer member and accessor are compiled only when
JSON_DIAGNOSTIC_POSITIONS is enabled, which is already part of the ABI
tag, so the default build is unaffected.
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
* Add implementation to retrieve start and end positions of json during parse
* Add more unit tests and add start/stop parsing for arrays
* Add raw value for all types
* Add more tests and fix compiler warning
* Amalgamate
* Fix CLang GCC warnings
* Fix error in build
* Style using astyle 3.1
* Fix whitespace changes
* revert
* more whitespace reverts
* Address PR comments
* Fix failing issues
* More whitespace reverts
* Address remaining PR comments
* Address comments
* Switch to using custom base class instead of default basic_json
* Adding a basic using for a json using the new base class. Also address PR comments and fix CI failures
* Address decltype comments
* Diagnostic positions macro (#4)
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Fix missed include deletion
* Add docs and address other PR comments (#5)
* Add docs and address other PR comments
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Address new PR comments and fix CI tests for documentation
* Update documentation based on feedback (#6)
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Address std::size_t and other comments
* Fix new CI issues
* Fix lcov
* Improve lcov case with update to handle_diagnostic_positions call for discarded values
* Fix indentation of LCOV_EXCL_STOP comments
* fix amalgamation astyle issue
---------
Co-authored-by: Sush Shringarputale <sushring@linux.microsoft.com>
* Add versioned inline namespace
Add a versioned inline namespace to prevent ABI issues when linking code
using multiple library versions.
* Add namespace macros
* Encode ABI information in inline namespace
Add _diag suffix to inline namespace if JSON_DIAGNOSTICS is enabled, and
_ldvcmp suffix if JSON_USE_LEGACY_DISCARDED_VALUE_COMPARISON is enabled.
* Move ABI-affecting macros into abi_macros.hpp
* Move std_fs namespace definition into std_fs.hpp
* Remove std_fs namespace from unit test
* Format more files in tests directory
* Add unit tests
* Update documentation
* Fix GDB pretty printer
* fixup! Add namespace macros
* Derive ABI prefix from NLOHMANN_JSON_VERSION_*
* Make exception context optional
Change exception context parameter to pointer and replace context with
nullptr where appropriate.
* Support escaping other string types
* Add string concatenation function
Add variadic concat() function for concatenating char *, char, and
string types.
* Replace string concatenations using + with concat()
* Template json_pointer on string type
Change json_pointer from being templated on basic_json to being
templated on string type.
* Add unit test for #3388Closes#3388.
* Fix regression test for #2958
* Add backwards compatibility with json_pointer<basic_json>
* Update json_pointer docs
* Allow comparing different json_pointers
* Update version numbers