[jhodges10]

Summary

RapidJSON treats a raw NUL byte as end-of-input. Both JSON entry points could therefore accept a valid prefix such as {"x":1}\0{"y":2} while silently ignoring the rest. Reject these inputs so callers cannot disagree about what was parsed.

Changes

• Parse strings through a length-aware MemoryStream and reject a successful parse that consumed fewer bytes than the supplied string.
• Distinguish a real NUL byte from FileReadStream's synthetic end-of-file marker after file parsing; open files in binary mode so Windows text-mode EOF translation cannot truncate input.
• Add a C++ regression test for both entry points, unchanged destination values on failure, and valid escaped \u0000 with trailing whitespace.

Validation

• The C++ serialization tests passed in Debug and under AddressSanitizer/UndefinedBehaviorSanitizer.
• Nine other CTest targets and eleven bundle cases passed; the disk-intensive ZIP64 case was omitted.
• A Python API smoke test confirmed both string and file deserialization now raise ValueError for the crafted input, while escaped \u0000 remains valid.

Assisted-by: OpenAI Codex / GPT-6 Daybreak (cyber-security model)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 55.55556% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.47%. Comparing base (0bfd9d6) to head (0f03940).

Files with missing lines	Patch %	Lines
src/opentimelineio/deserialization.cpp	55.55%	8 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2086      +/-   ##
==========================================
- Coverage   83.62%   83.47%   -0.16%     
==========================================
  Files         184      184              
  Lines       13627    13993     +366     
  Branches     1270     1274       +4     
==========================================
+ Hits        11395    11680     +285     
- Misses       2059     2140      +81     
  Partials      173      173              

Flag	Coverage Δ
py-unittests	83.47% <55.55%> (-0.16%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/opentimelineio/deserialization.cpp	63.18% <55.55%> (+0.29%)	⬆️

... and 63 files with indirect coverage changes

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