A picture is worth a thousand message digests #1949
Closed
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
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.
|
Note that something like this seems to be a prerequisite for several improvements and fixes to GD. For instance, I wanted to fix https://bugs.php.net/64641, but the fix caused several tests to fail. As it turned out, the failure was due to minimal differences introduced by fixing the bug. However, inspecting the failures caused by the md5() verification is cumbersome; test_image_equals_file() is supposed to considerably alleviate this problem. |
|
Comment on behalf of cmb at php.net: Cherry-picked into PHP-5.6+ with commit dc09f30. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
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.