Pass the `$post` object as context to `postmeta_form_keys`.

see #33885, #18979.

Built from https://develop.svn.wordpress.org/trunk@35730


git-svn-id: http://core.svn.wordpress.org/trunk@35694 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/template.php

@@ -584,8 +584,9 @@ function meta_form( $post = null ) {
 	 * @since 4.4.0
 	 *
 	 * @param array|null $keys Pre-defined meta keys to be used in place of a postmeta query. Default null.
+	 * @param WP_Post    $post The current post object.
 	 */
-	$keys = apply_filters( 'postmeta_form_keys', null );
+	$keys = apply_filters( 'postmeta_form_keys', null, $post );
 
 	if ( null === $keys ) {
 		/**

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.4-beta4-35729';
+$wp_version = '4.4-beta4-35730';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.