[libpng16] test: Add a compile-time check in pngimage.c to avoid a failure

Disable the check on `interlace_method` inside function `compare_read`
in pngimage.c, if WRITE_INTERLACING is not supported.

If interlaced encoding is disabled inside libpng, the encoded images
are non-interlaced silently and unconditionally.  This commit updates
the image comparison to skip the interlace check in the resultant
image; other behavior is still checked.

This is a cherry-pick of commit d9f13d8d846e08b00f6530b7a5fe07039d48c78d
from branch 'libpng18'.

Reviewed-by: Cosmin Truta <ctruta@gmail.com>
Signed-off-by: John Bowler <jbowler@acm.org>
Signed-off-by: Cosmin Truta <ctruta@gmail.com>
1 file changed