Libjpeg used in NetSurf for decoding of JPEG images handles exceptions using a
pair of non-local jump functions: setjmp() and longjmp(). When a decompression
context is created via a call to the function jpeg_create_decompress() the
caller passes a structure jpeg_decompress_struct as a parameter. This structure
should has a validly initialized jump buffer, so the initialization or other
functions called in future can jump to the exception handling context.
The jpeg backend of NetSurf now initializes libjpeg mistakenly: jump buffer is
filled after the call to jpeg_create_decompress(). It results in jump to random
addresses in the case of exception caught during operation of the function
jpeg_create_decompress().
The patch moves the initialization of jump buffer before the call to
jpeg_create_decompress().
Signed-off-by: Sergei Rogachev <rogachevsergei@gmail.com>
