Fixes: da14e86d8462be6493eab16bc2d40f88/asan_heap-oob_204cfd2_528_cov_340150052_COMPRESS.BMP

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>