Check if the `$post_type` passed to `get_post_type_object()` is a `scalar` value. Non-scalars were producing PHP warnings.

Adds unit tests.

Props Kloon.
Fixes #30013.

Built from https://develop.svn.wordpress.org/trunk@34100


git-svn-id: http://core.svn.wordpress.org/trunk@34068 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/post-functions.php

@@ -835,10 +835,11 @@ function get_post_type( $post = null ) {
 function get_post_type_object( $post_type ) {
 	global $wp_post_types;
 
-	if ( empty($wp_post_types[$post_type]) )
+	if ( ! is_scalar( $post_type ) || empty( $wp_post_types[ $post_type ] ) ) {
 		return null;
+	}
 
-	return $wp_post_types[$post_type];
+	return $wp_post_types[ $post_type ];
 }
 
 /**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-alpha-34099';
+$wp_version = '4.4-alpha-34100';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.