On Thu, 10 Apr 2025 07:20:06 GMT, Jeremy Wood <d...@openjdk.org> wrote:
>> I do not have much background in LZW compression or in C, but I'm reasonably >> confident this resolves the problem I'm observing. It looks like the >> GifImageDecoder was not always correctly handling compression codes after >> the table reached its limit of ~4096. If anyone has suggestions for >> improvements I'm happy to make adjustments. >> >> Luckily while debugging this: I was able to compare the flawed >> implementation (GifImageDecoder) with ImageIO's implementation >> (GIFImageReader) to help identify how the suffix/prefix tables are supposed >> to work. >> >> ImageIO's implementation may have suffered a similar bug (maybe >> https://bugs.openjdk.org/browse/JDK-7131823 ?), and that appears to have >> been backported. >> >> I have dozens of additional test cases for this problem, but unfortunately I >> don't have the rights to commit them to the OpenJDK repo. Feel free to email >> me for additional context/test cases. > > Jeremy Wood has updated the pull request incrementally with one additional > commit since the last revision: > > 8351913: changing whitespace (PR review) I see this PR. Need someone to review it properly as it seems to require non-superficial understanding of what is going on. ------------- PR Comment: https://git.openjdk.org/jdk/pull/24271#issuecomment-2831430009
