V3: Do not attempt to decode iDAT chunks when image is fully decoded. #2927
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Pull Request Overview
This PR backports a fix for issue #2924 to v3.1.x, ensuring that iDAT chunks are not decoded once the image is fully processed.
- Adds new test images and a constant for Issue2924 to the test assets.
- Introduces a new unit test in PngDecoderTests to validate the fix.
- Updates PngDecoderCore by adding a flag (hasImageData) and refactoring control flow with goto EXIT statements to set that flag.
Reviewed Changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.
Show a summary per file
| File | Description |
|---|---|
| tests/Images/Input/Png/issues/Issue_2924.png | Added test image metadata for issue 2924 |
| tests/Images/External/ReferenceOutput/PngDecoderTests/CanDecode_Issue2924_Rgba32_Issue_2924.png | Added reference output image for issue 2924 |
| tests/ImageSharp.Tests/TestImages.cs | Added a constant for the new issue-specific test image |
| tests/ImageSharp.Tests/Formats/Png/PngDecoderTests.cs | Added a new unit test for verifying the decoding fix |
| src/ImageSharp/Formats/Png/PngDecoderCore.cs | Introduced hasImageData flag and refactored control flow to prevent decoding iDAT chunks when the image is complete |
This was referenced Jul 23, 2025
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Prerequisites
Description
Fixes #2924
Backport of #2926 for v3.1.x