Embeds: Enforce a valid post ID when embedding a post from the current site.

Otherwise `wp_filter_pre_oembed_result()` could erroneously return the HTML of the current post instead of the intended result.

Props kraftbj.
See #36767.
Built from https://develop.svn.wordpress.org/trunk@37729


git-svn-id: http://core.svn.wordpress.org/trunk@37695 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/embed.php

@@ -1100,6 +1100,10 @@ function wp_filter_pre_oembed_result( $result, $url, $args ) {
 	/** This filter is documented in wp-includes/class-wp-oembed-controller.php */
 	$post_id = apply_filters( 'oembed_request_post_id', $post_id, $url );
 
+	if ( ! $post_id ) {
+		return $result;
+	}
+
 	$width = isset( $args['width'] ) ? $args['width'] : 0;
 
 	$data = get_oembed_response_data( $post_id, $width );

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-alpha-37728';
+$wp_version = '4.6-alpha-37729';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.