Commit Graph
8 Commits
Author SHA1 Message Date
Niels Lohmann 8c38e270b5 Reject JSON Patch move when from is a proper prefix of path (#5497)
* Reject JSON Patch move when from is a proper prefix of path

RFC 6902 (section 4.4) forbids "from" from being a proper prefix of
"path" for a "move" operation: "a location cannot be moved into one
of its children." "move" is implemented as remove-then-add with no
check for this. For object targets, the subsequent "add" happened to
throw as a side effect of resolving through the now-removed parent,
but for array targets, removing the "from" element shifts subsequent
indices, so "path" silently re-resolves to a different element and
the operation "succeeds" with a silently corrupted document.

Add a check, before performing the remove/add, for whether "from" is
a proper prefix of "path" at the reference-token level. This compares
json_pointer's already-unescaped reference_tokens vectors (basic_json
is a friend of json_pointer) rather than the raw pointer strings, so
that tokens containing escaped '/' or '~' characters are compared
correctly, and a token that merely looks like a string prefix (e.g.
"/ab" vs "/abc/x") is not mistaken for a pointer-token prefix. When
"from" is a proper prefix of "path", throw out_of_range.414.

Fixes #5397.

Stacked on top of the fix for #5396 (branch
issue-5396-patch-remove-primitive-parent), since both touch the same
patch_inplace move/remove handling in include/nlohmann/json.hpp.

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

* Add root-pointer and array-append-token edge case tests for the move prefix check

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

* Replace std::equal with an explicitly-bounded loop in the move prefix check

The three-iterator std::equal(first1, last1, first2) form has no
explicit end iterator for the second range, which a static analyzer
(Flawfinder, CWE-126) flags as a potential over-read even though the
preceding size comparison already guarantees the second range is long
enough. Rather than argue the point, make the bound visible in the code
itself via an explicit loop -- every access to ptr.reference_tokens is
now guarded by the same index the loop condition bounds against
from_size.

(The C++14 four-iterator std::equal(first1, last1, first2, last2) form
was tried first as a more minimal fix, but this codebase targets C++11
and that overload is not safely usable under -std=c++11 with all
supported standard library implementations.)

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

* Extract the move prefix check into a named helper lambda

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

* Account for JSON_DIAGNOSTIC_POSITIONS in the move-prefix-check error messages

out_of_range::create() includes a "(bytes X-Y)" position annotation when
JSON_DIAGNOSTIC_POSITIONS is enabled, which the ci_test_diagnostic_positions
CI job builds the whole suite with. The five new out_of_range.414
assertions only checked the annotation-free message. Confirmed
JSON_DIAGNOSTICS produces the same (annotation-free) message as the
default build for this particular throw site (its path-based annotation
is empty at the root, where &result always points here), so only two
message variants are needed, not three.

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-09 09:49:12 +02:00
Niels Lohmann c9477ccf91 Throw when JSON Patch remove's target path resolves through a primitive or null parent (#5496)
RFC 6902 (section 4.2) requires the target location of a "remove"
operation to exist. operation_remove handled parent.is_object() and
parent.is_array(), but had no final else branch: when the resolved
parent was a primitive value or null, neither branch matched and the
operation silently did nothing instead of failing.

Add the missing else branch, throwing out_of_range.413 with wording
that matches the existing out_of_range.411 thrown by the analogous
"add" case (operation_add) for the same kind of invalid parent.

Fixes #5396.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-09 09:49:12 +02:00
Niels Lohmann 521a084827 Documentation review (#5257)
* 📝 Fix documentation gaps for 3.13.0 release (todos 138-142)

- Todo 138: Add "Known issues" section to modules.md with compiler-specific troubleshooting (GCC redefinition, MSVC symbol export). Add pointer note to quality_assurance.md.
- Todo 139: Document CBOR/MessagePack half-precision float encoding for NaN/Infinity (0xF9/0xCA with exact byte sequences). Explain pre-3.13.0 double-precision bug mechanism without issue citations.
- Todo 140: Document CBOR negative-integer-overflow rejection (parse_error.112) for magnitudes exceeding int64_t range (already implemented in rev 1).
- Todo 141: Update version history in value.md and operator[].md with behavior-change details, removing issue citations per citation policy (prose is self-contained).
- Todo 142: Global sed replace of 3.12.x → 3.13.0 placeholder across all 20 documentation files.

Revision 2 incorporates feedback to reduce changelog-like issue citations. Only citations that add unique troubleshooting value are retained (#5103 for GCC workaround, #3970 for MSVC symbol export). "Known issues" section follows PR #5252's visual pattern (info admonition with bold-bullet format).

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

* 📝 Document integer type selection, type_name() invalid value, and std::optional get() fix

- number_handling.md: clarify that positive/negative integers select
  unsigned/signed storage based on the leading minus sign (todo 143).
- type_name.md: document the new "invalid" return value for corrupted
  JSON values (todo 145).
- get.md: note that get<std::optional<T>>() was unreachable in every
  configuration prior to 3.13.0 due to an internal macro-guard bug,
  unrelated to JSON_USE_IMPLICIT_CONVERSIONS's actual effect (todo 144).

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

---------

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-07-09 17:24:19 +02:00
Niels Lohmann 730b57775d 🐛 avoid assertion in patch (#5222) 2026-07-01 06:47:24 +02:00
Niels Lohmann c5b2b26fdc 📝 fix docs (#5217) 2026-06-29 22:15:18 +02:00
Niels Lohmann 4424a0fcc1 📝 update documentation (#4723)
Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2025-04-05 18:54:35 +02:00
Niels Lohmann b185c5bc9d 📝 clean up after #3581 (#3596) 2022-07-22 15:35:29 +02:00
Wolf Vollprecht 09fb4819ff add patch_inplace function (#3581)
* add patch_inplace function to json class

* add documentation

* fix up docs
2022-07-21 16:27:59 +02:00