Ticket #34528: 34528.diff

src/wp-includes/media.php

@@ -972 +972 @@
                 return false;
         }
 
+        // Don't add srcset attributes to animated gifs. See #28474.
+        if ( 'image/gif' === $image_sizes['thumbnail']['mime-type'] && false !== strpos( $image_name, $image_meta['file'] ) ) {
+                return false;
+        }
+
         // Add full size to the '$image_sizes' array.
         $image_sizes['full'] = array(
                 'width'  => $image_meta['width'],

tests/phpunit/tests/media.php

@@ -949 +949 @@
                 // The content filter should return the image unchanged.
                 $this->assertSame( $image_html, wp_make_content_images_responsive( $image_html ) );
         }
+
+        /**
+         * @ticket 33641
+         * @ticket 34528
+         */
+        function test_wp_calculate_image_srcset_animated_gifs() {
+                // Mock meta for an animated gif.
+                $image_meta = array(
+                        'width' => 1200,
+                        'height' => 600,
+                        'file' => 'animated.gif',
+                        'sizes' => array(
+                                'thumbnail' => array(
+                                        'file' => 'animated-150x150.gif',
+                                        'width' => 150,
+                                        'height' => 150,
+                                        'mime-type' => 'image/gif'
+                                ),
+                                'medium' => array(
+                                        'file' => 'animated-300x150.gif',
+                                        'width' => 300,
+                                        'height' => 150,
+                                        'mime-type' => 'image/gif'
+                                ),
+                                'large' => array(
+                                        'file' => 'animated-1024x512.gif',
+                                        'width' => 1024,
+                                        'height' => 512,
+                                        'mime-type' => 'image/gif'
+                                ),
+                        )
+                );
+
+                $image_name = 'http://' . WP_TESTS_DOMAIN . '/wp-content/uploads/' . $image_meta['file'];
+                // Test with soft resized size array.
+                $size_array = array(900, 450);
+
+                $this->assertFalse( wp_calculate_image_srcset( $image_name, $size_array, $image_meta ) );
+        }
 }