Changeset 35561

Timestamp:

11/07/2015 02:09:56 AM (9 years ago)

Author:

azaozz

Message:

Responsive images: omit full size images from srcset attributes when the original file is an intermediate sized GIF so we don't accidentally add animation to an otherwise flat image. Update the tests to cover this case.

Props joemcgill, H-Shredder, SergeyBiryukov.
Fixes #34528.

Location:

trunk

Files:

• src/wp-includes/media.php (modified) (1 diff)
• tests/phpunit/tests/media.php (modified) (1 diff)

trunk/src/wp-includes/media.php

@@ -984 +984 @@
     }
 
-    // Don't add srcset attributes to (animated) gifs that are inserted at full size.
-    if ( isset( $image_sizes['thumbnail']['mime-type'] ) && 'image/gif' === $image_sizes['thumbnail']['mime-type'] &&
-        false !== strpos( $image_src, $image_meta['file'] ) ) {
-
-        return false;
-    }
-
     $image_basename = wp_basename( $image_meta['file'] );
     $image_baseurl = _wp_upload_dir_baseurl();
 
-    // Add full size to the '$image_sizes' array.
-    $image_sizes['full'] = array(
-        'width'  => $image_meta['width'],
-        'height' => $image_meta['height'],
-        'file'   => $image_basename,
-    );
+    /*
+     * WordPress flattens animated GIFs into one frame when generating intermediate sizes.
+     * To avoid hiding animation in user content, if src is a full size GIF, a srcset attribute is not generated.
+     * If src is an intermediate size GIF, the full size is excluded from srcset to keep a flattened GIF from becoming animated.
+     */
+    if ( ! isset( $image_sizes['thumbnail']['mime-type'] ) || 'image/gif' !== $image_sizes['thumbnail']['mime-type'] ) {
+        $image_sizes['full'] = array(
+            'width'  => $image_meta['width'],
+            'height' => $image_meta['height'],
+            'file'   => $image_basename,
+        );
+    } elseif ( strpos( $image_src, $image_meta['file'] ) ) {
+        return false;
+    }
 
     // Uploads are (or have been) in year/month sub-directories.

trunk/tests/phpunit/tests/media.php

@@ -1013 +1013 @@
         );
 
-        $image_src = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . $image_meta['file'];
+        $full_src  = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . $image_meta['file'];
+        $large_src = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . $image_meta['sizes']['large']['file'];
+
         // Test with soft resized size array.
         $size_array = array(900, 450);
 
-        $this->assertFalse( wp_calculate_image_srcset( $image_src, $size_array, $image_meta ) );
+        // Full size GIFs should not return a srcset.
+        $this->assertFalse( wp_calculate_image_srcset( $full_src, $size_array, $image_meta ) );
+        // Intermediate sized GIFs should not include the full size in the srcset.
+        $this->assertFalse( strpos( wp_calculate_image_srcset( $large_src, $size_array, $image_meta ), $full_src ) );
     }
 }