Ticket #34807: 34807.patch

src/wp-includes/media.php

@@ -1206 +1206 @@
  * @return string Converted content with 'srcset' and 'sizes' attributes added to images.
  */
 function wp_make_content_images_responsive( $content ) {
-        $images = get_media_embedded_in_content( $content, 'img' );
+        if ( ! preg_match_all( '/<img [^>]+>/', $content, $matches ) ) {
+                return $content;
+        }
 
         $selected_images = $attachment_ids = array();
 
-        foreach( $images as $image ) {
+        foreach( $matches[0] as $image ) {
                 if ( false === strpos( $image, ' srcset=' ) && preg_match( '/wp-image-([0-9]+)/i', $image, $class_id ) &&
                         ( $attachment_id = absint( $class_id[1] ) ) ) {