Only exit JPEG scan decoding after multiple EOF hits

JimBobSquarePants commented 4 months ago

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Fixes #2638

Updates the JpegBitReader to only exit after we've hit the end of the file multiple times. This ensures that we do not skip over the last MCU.

cc @br3aker

br3aker commented 3 months ago

Brilliant! Spent countless evenings thinking how to achieve this without sacrificing performance/DOS defense....

JimBobSquarePants commented 3 months ago

Brilliant! Spent countless evenings thinking how to achieve this without sacrificing performance/DOS defense....

I actually got the idea from changes @antonfirsov made to BufferedReadStream.

SixLabors / ImageSharp