Commit 98ff1fd10306d031cfcf8a6becf78b3ac0afe49b

DRC 2022-11-21T20:57:39

TurboJPEG: Add lossless JPEG detection capability Add a new TurboJPEG C API function (tjDecompressHeader4()) and Java API method (TJDecompressor.getFlags()) that return the bitwise OR of any flags that are relevant to the JPEG image being decompressed (currently TJFLAG_PROGRESSIVE, TJFLAG_ARITHMETIC, TJFLAG_LOSSLESS, and their Java equivalents.) This allows a calling program to determine whether the image being decompressed is a lossless JPEG image, which means that the decompression scaling feature will not be available and that a full-sized destination buffer should be allocated. More specifically, this fixes a buffer overrun in TJBench, TJExample, and the decompress* fuzz targets that occurred when attempting (in vain) to decompress a lossless JPEG image with decompression scaling enabled.