Check attachments as well as the current post type when checking for duplicate post slugs. This avoids creating a page with a slug which conflicts with an existing attachment (the inverse is already handled).

Updates the existing test for pages which should take priority over attachments in cases where an existing clash exists.

Fixes #18962
Props boonebgorges

Built from https://develop.svn.wordpress.org/trunk@30629


git-svn-id: http://core.svn.wordpress.org/trunk@30619 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/post.php

@@ -3703,7 +3703,7 @@ function wp_unique_post_slug( $slug, $post_ID, $post_status, $post_type, $post_p
 		 * Page slugs must be unique within their own trees. Pages are in a separate
 		 * namespace than posts so page slugs are allowed to overlap post slugs.
 		 */
-		$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type = %s AND ID != %d AND post_parent = %d LIMIT 1";
+		$check_sql = "SELECT post_name FROM $wpdb->posts WHERE post_name = %s AND post_type IN ( %s, 'attachment' ) AND ID != %d AND post_parent = %d LIMIT 1";
 		$post_name_check = $wpdb->get_var( $wpdb->prepare( $check_sql, $slug, $post_type, $post_ID, $post_parent ) );
 
 		/**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.1-beta2-30628';
+$wp_version = '4.1-beta2-30629';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.