Embeds: Filter HTML response in oEmbed proxy controller.

Adapts the response from `WP_oEmbed_Controller::get_proxy_item()` so that the response is correctly filtered and embeds work properly in JavaSccript editors. Introduces new `get_oembed_response_data_for_url()` function for preparing internal oEmbed responses.

Merges [43810] from the 5.0 branch to trunk.

Props danielbachhuber, imath, swissspidy.
Fixes #45142.


Built from https://develop.svn.wordpress.org/trunk@44154


git-svn-id: http://core.svn.wordpress.org/trunk@43984 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-oembed.php

@@ -404,9 +404,9 @@ class WP_oEmbed {
 		 *
 		 * @since 2.9.0
 		 *
-		 * @param string $data The returned oEmbed HTML.
-		 * @param string $url  URL of the content to be embedded.
-		 * @param array  $args Optional arguments, usually passed from a shortcode.
+		 * @param string|false $data The returned oEmbed HTML (false if unsafe).
+		 * @param string       $url  URL of the content to be embedded.
+		 * @param array        $args Optional arguments, usually passed from a shortcode.
 		 */
 		return apply_filters( 'oembed_result', $this->data2html( $data, $url ), $url, $args );
 	}

wp-includes/class-wp-oembed-controller.php

@@ -181,12 +181,22 @@ final class WP_oEmbed_Controller {
 			$args['height'] = $args['maxheight'];
 		}
 
+		// Short-circuit process for URLs belonging to the current site.
+		$data = get_oembed_response_data_for_url( $url, $args );
+
+		if ( $data ) {
+			return $data;
+		}
+
 		$data = _wp_oembed_get_object()->get_data( $url, $args );
 
 		if ( false === $data ) {
 			return new WP_Error( 'oembed_invalid_url', get_status_header_desc( 404 ), array( 'status' => 404 ) );
 		}
 
+		/** This filter is documented in wp-includes/class-oembed.php */
+		$data->html = apply_filters( 'oembed_result', _wp_oembed_get_object()->data2html( (object) $data, $url ), $url, $args );
+
 		/**
 		 * Filters the oEmbed TTL value (time to live).
 		 *

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-44153';
+$wp_version = '5.1-alpha-44154';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.