Editor: Cast the result of the default_content, default_title, and default_excerpt filters.

pento · pento · commit fe56c5deb3a4 · 2018-11-01T05:19:48.000Z
If a plugin returns a non-string value (or returns `null`) on these filters, it can cause errors in the block editor. Casting them as a string prevents these errors. Props dd32. See #45236. git-svn-id: https://develop.svn.wordpress.org/branches/5.0@43858 602fd350-edb4-49c9-b593-d223f7449a82
diff --git a/src/wp-admin/includes/post.php b/src/wp-admin/includes/post.php
@@ -639,7 +639,7 @@ function get_default_post_to_edit( $post_type = 'post', $create_in_db = false )
 	 * @param string  $post_content Default post content.
 	 * @param WP_Post $post         Post object.
 	 */
-	$post->post_content = apply_filters( 'default_content', $post_content, $post );
+	$post->post_content = (string) apply_filters( 'default_content', $post_content, $post );
 
 	/**
 	 * Filters the default post title initially used in the "Write Post" form.
@@ -649,7 +649,7 @@ function get_default_post_to_edit( $post_type = 'post', $create_in_db = false )
 	 * @param string  $post_title Default post title.
 	 * @param WP_Post $post       Post object.
 	 */
-	$post->post_title = apply_filters( 'default_title', $post_title, $post );
+	$post->post_title = (string) apply_filters( 'default_title', $post_title, $post );
 
 	/**
 	 * Filters the default post excerpt initially used in the "Write Post" form.
@@ -659,7 +659,7 @@ function get_default_post_to_edit( $post_type = 'post', $create_in_db = false )
 	 * @param string  $post_excerpt Default post excerpt.
 	 * @param WP_Post $post         Post object.
 	 */
-	$post->post_excerpt = apply_filters( 'default_excerpt', $post_excerpt, $post );
+	$post->post_excerpt = (string) apply_filters( 'default_excerpt', $post_excerpt, $post );
 
 	return $post;
 }
