Media: Prevent image_get_intermediate_size() from returning cropped images.

When `$size` is passed to `image_get_intermediate_size()` as an array of width
and height values and an exact image size matching those values isn't available,
the function loops through the available attachment sizes and returns the
smallest image larger than the requested dimensions with the same aspect ratio.

The aspect ratio check is skipped for the 'thumbnail' size to provide a fallback
for small sizes when no other image option is available. This resulted in a poor
selection when the size requested was smaller than the 'thumbnail' dimensions
but a larger size matching the requested ratio existed.

This refactors the internals of `image_get_intermediate_size()` to ensure the
'thumbnail' size is only returned as a fallback to small sizes once all other
options have been considered, and makes the control flow easier to follow.

This also introduces a new helper function, `wp_image_matches_ratio()` for
testing whether the aspect ratios of two sets of dimensions match. This function
is also now used in `wp_calculate_image_srcset()` during the selection process.

Props flixos, joemcgill.
Fixes #34384, #34980.

git-svn-id: https://develop.svn.wordpress.org/trunk@38086 602fd350-edb4-49c9-b593-d223f7449a82
This commit is contained in:
Joe McGill
2016-07-18 02:13:45 +00:00
parent 38bcf065df
commit a91e769e36
2 changed files with 110 additions and 50 deletions
@@ -224,4 +224,38 @@ class Tests_Image_Intermediate_Size extends WP_UnitTestCase {
$this->assertTrue( strpos( $image['file'], $width . 'x' . $height ) > 0 );
}
/**
* @ticket 34384
*/
public function test_get_intermediate_size_with_small_size_array() {
// Add a hard cropped size that matches the aspect ratio we're going to test.
add_image_size( 'test-size', 200, 100, true );
$file = DIR_TESTDATA . '/images/waffles.jpg';
$id = $this->_make_attachment( $file, 0 );
// Request a size by array that doesn't exist and is smaller than the 'thumbnail'
$image = image_get_intermediate_size( $id, array( 50, 25 ) );
// We should get the 'test-size' file and not the thumbnail.
$this->assertTrue( strpos( $image['file'], '200x100' ) > 0 );
}
/**
* @ticket 34384
*/
public function test_get_intermediate_size_with_small_size_array_fallback() {
$file = DIR_TESTDATA . '/images/waffles.jpg';
$id = $this->_make_attachment( $file, 0 );
$original = wp_get_attachment_metadata( $id );
$thumbnail_file = $original['sizes']['thumbnail']['file'];
// Request a size by array that doesn't exist and is smaller than the 'thumbnail'
$image = image_get_intermediate_size( $id, array( 50, 25 ) );
// We should get the 'thumbnail' file as a fallback.
$this->assertSame( $image['file'], $thumbnail_file );
}
}