Rewrite: Redirect attachment URLs when their slug changes.

Using the same logic that we use to redirect posts when their slug changes, we can provide the same functionality for attachments. Attachment pages are posts, too.

Props swissspdy.

Fixes #34043.


Built from https://develop.svn.wordpress.org/trunk@34685


git-svn-id: http://core.svn.wordpress.org/trunk@34649 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/default-filters.php

@@ -294,8 +294,9 @@ add_action( 'begin_fetch_post_thumbnail_html', '_wp_post_thumbnail_class_filter_
 add_action( 'end_fetch_post_thumbnail_html',   '_wp_post_thumbnail_class_filter_remove' );
 
 // Redirect Old Slugs
-add_action( 'template_redirect', 'wp_old_slug_redirect'              );
-add_action( 'post_updated',      'wp_check_for_changed_slugs', 12, 3 );
+add_action( 'template_redirect',  'wp_old_slug_redirect'              );
+add_action( 'post_updated',       'wp_check_for_changed_slugs', 12, 3 );
+add_action( 'attachment_updated', 'wp_check_for_changed_slugs', 12, 3 );
 
 // Nonce check for Post Previews
 add_action( 'init', '_show_post_preview' );

wp-includes/post-functions.php

@@ -1330,7 +1330,7 @@ function _post_type_meta_capabilities( $capabilities = null ) {
  * @since 4.3.0 Added the `featured_image`, `set_featured_image`, `remove_featured_image`,
  *              and `use_featured_image` labels.
  * @since 4.4.0 Added the `insert_into_item` and `uploaded_to_this_item` labels.
- * 
+ *
  * @access private
  *
  * @param object $post_type_object Post type object.
@@ -3280,6 +3280,18 @@ function wp_insert_post( $postarr, $wp_error = false ) {
 			 * @param int $post_ID Attachment ID.
 			 */
 			do_action( 'edit_attachment', $post_ID );
+			$post_after = get_post( $post_ID );
+
+			/**
+			 * Fires once an existing attachment has been updated.
+			 *
+			 * @since 4.4.0
+			 *
+			 * @param int     $post_ID      Post ID.
+			 * @param WP_Post $post_after   Post object following the update.
+			 * @param WP_Post $post_before  Post object before the update.
+			 */
+			do_action( 'attachment_updated', $post_ID, $post_after, $post_before );
 		} else {
 
 			/**
@@ -5133,23 +5145,27 @@ function wp_mime_type_icon( $mime = 0 ) {
  * @param WP_Post $post_before The Previous Post Object
  */
 function wp_check_for_changed_slugs( $post_id, $post, $post_before ) {
-	// Don't bother if it hasnt changed.
-	if ( $post->post_name == $post_before->post_name )
+	// Don't bother if it hasn't changed.
+	if ( $post->post_name == $post_before->post_name ) {
 		return;
+	}
 
 	// We're only concerned with published, non-hierarchical objects.
-	if ( $post->post_status != 'publish' || is_post_type_hierarchical( $post->post_type ) )
+	if ( ! ( 'publish' === $post->post_status || ( 'attachment' === get_post_type( $post ) && 'inherit' === $post->post_status ) ) || is_post_type_hierarchical( $post->post_type ) ) {
 		return;
+	}
 
-	$old_slugs = (array) get_post_meta($post_id, '_wp_old_slug');
+	$old_slugs = (array) get_post_meta( $post_id, '_wp_old_slug' );
 
 	// If we haven't added this old slug before, add it now.
-	if ( !empty( $post_before->post_name ) && !in_array($post_before->post_name, $old_slugs) )
-		add_post_meta($post_id, '_wp_old_slug', $post_before->post_name);
+	if ( ! empty( $post_before->post_name ) && ! in_array( $post_before->post_name, $old_slugs ) ) {
+		add_post_meta( $post_id, '_wp_old_slug', $post_before->post_name );
+	}
 
 	// If the new slug was used previously, delete it from the list.
-	if ( in_array($post->post_name, $old_slugs) )
-		delete_post_meta($post_id, '_wp_old_slug', $post->post_name);
+	if ( in_array( $post->post_name, $old_slugs ) ) {
+		delete_post_meta( $post_id, '_wp_old_slug', $post->post_name );
+	}
 }
 
 /**

wp-includes/query.php

@@ -4736,12 +4736,15 @@ function wp_old_slug_redirect() {
 		global $wpdb;
 
 		// Guess the current post_type based on the query vars.
-		if ( get_query_var('post_type') )
-			$post_type = get_query_var('post_type');
-		elseif ( !empty($wp_query->query_vars['pagename']) )
+		if ( get_query_var( 'post_type' ) ) {
+			$post_type = get_query_var( 'post_type' );
+		} elseif ( get_query_var( 'attachment' ) ) {
+			$post_type = 'attachment';
+		} elseif ( ! empty( $wp_query->query_vars['pagename'] ) ) {
 			$post_type = 'page';
-		else
+		} else {
 			$post_type = 'post';
+		}
 
 		if ( is_array( $post_type ) ) {
 			if ( count( $post_type ) > 1 )

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34684';
+$wp_version = '4.4-alpha-34685';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.