Apparently, different FreeType versions render the string differently, so
we have to cater to these slight differences. Unfortunately, the testing
framework doesn't yet offer a clean API for this, so we work around the
limitations by parsing and checking the output of test_image_equals_file().
The behavior of imagecropauto($im, IMG_CROP_DEFAULT) is rather different
for the bundled and an external libgd, see
<https://github.com/libgd/libgd/issues/298>.
Therefore we split the test for now.
This test case fails with external libgd, because libgd < 2.2.4 converts
palette images to truecolor (<https://github.com/libgd/libgd/issues/297>).
However, even if there happens no truecolor conversion, it is not guaranteed
that the palette indexes of the original and the cropped image are identical
(this is, for instance, not the case with current libgd master where the bug
has been fixed). Therefore we check for the expected RGBA value instead of
the palette index.
The bundled GD test suites makes heavy use of md5() to verify the result
of drawing operations. This leads to fragile tests (even a slight change
in a PNG header would cause failure, and of course there is the
possibility of collisions), and even worse, eventual test failures are
rather unrevealing.
Therefore we replace all md5() verification with a simplistic
test_image_equals_file(), which is basically a simplified port of libgd's
gdTestImageCompareToFile(), adapted to the needs of PHPTs.
In the long run better tests helpers should be introduced (see also
<http://news.php.net/php.internals/94081>), but for now this solution
is preferable over the former.
(cherry picked from commit 24f9e96792)
The test succeeds with libxml < 2.9.4, and is supposed to succeed with
libxml > 2.9.4. Unfortunately, we can't conditionally mark a test case
as XFAIL, so we're simply skipping the test for libxml 2.9.4 instead.
...from FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE
The remainer of the fix would require the filter functions to only
convert to string when it makes sense for that particular filter.
(cherry picked from commit 432dc527ad)
