Ticket #34437: 34437.diff

src/wp-includes/media.php

@@ -3143 +3143 @@
 
                         /** This filter is documented in wp-includes/media.php */
                         if ( $downsize = apply_filters( 'image_downsize', false, $attachment->ID, $size ) ) {
-                                if ( ! $downsize[3] )
+                                if ( empty( $downsize[3] ) ) {
                                         continue;
+                                }
+
                                 $sizes[ $size ] = array(
                                         'height'      => $downsize[2],
                                         'width'       => $downsize[1],