Ticket #7392: 7392.2.diff

wp-admin/includes/post.php

@@ -1278 +1278 @@
  * @return unknown
  */
 function wp_create_post_autosave( $post_id ) {
+        if ( ! $post = get_post( $post_id ) )
+                return;
+
         $translated = _wp_translate_postdata( true );
         if ( is_wp_error( $translated ) )
                 return $translated;
 
         $post_author = get_current_user_id();
+        $new_data = $_POST;
 
         // Store one autosave per author. If there is already an autosave, overwrite it.
         if ( $old_autosave = wp_get_post_autosave( $post_id, $post_author ) ) {
@@ -1290 +1294 @@
                 $new_autosave['ID'] = $old_autosave->ID;
                 $new_autosave['post_author'] = $post_author;
 
+                // check to see if post content has changed before autosaving (filterable with wp_save_post_revision_check_for_changes)
+                if ( apply_filters( 'wp_save_post_revision_check_for_changes', true, $post, $new_data ) && is_array( $new_data ) ) {
+                        $post_has_changed = false;
+                        foreach ( array_keys( _wp_post_revision_fields() ) as $field ) {
+                                if ( normalize_whitespace( $new_data[ $field ] ) != normalize_whitespace( $post[ $field ] ) ) {
+                                        $post_has_changed = true;
+                                        break;
+                                }
+                        }
+                        // don't save revision if post unchanged
+                        if ( ! $post_has_changed )
+                                return;
+                }
+
                 // Auto-save revisioned meta fields.
                 foreach ( _wp_post_revision_meta_keys() as $meta_key ) {
                         if ( isset( $_POST[ $meta_key ] ) && get_post_meta( $new_autosave['ID'], $meta_key, true ) != $_POST[ $meta_key ] ) {