Ticket #23556: post.diff

post.php

@@ -4348 +4348 @@
 
         $file = get_attached_file( $post->ID );
 
-        if ( !empty($imagedata['thumb']) && ($thumbfile = str_replace(basename($file), $imagedata['thumb'], $file)) && file_exists($thumbfile) )
+        if ( isset($imagedata['sizes]['thumbnail']['file']) && !empty($imagedata['sizes]['thumbnail']['file']) && ($thumbfile = str_replace(basename($file), $imagedata['sizes']['thumbnail']['file], $file)) && file_exists($thumbfile) )
                 return apply_filters( 'wp_get_attachment_thumb_file', $thumbfile, $post->ID );
+        elseif ( !empty($imagedata['thumb']) && ($thumbfile = str_replace(basename($file), $imagedata['thumb'], $file)) && file_exists($thumbfile) )
+                return apply_filters( 'wp_get_attachment_thumb_file', $thumbfile, $post->ID );
         return false;
 }