Ticket #36345: 36345.patch

src/wp-includes/media.php

@@ -1008 +1008 @@
          * 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(
+                $image_sizes[] = array(
                         'width'  => $image_meta['width'],
                         'height' => $image_meta['height'],
                         'file'   => $image_basename,