Interactivity API: populate router's state.url in the server

Set the `core/router` state `url` property with the current page URL using `get_self_link()` when the first `data-wp-router-region` directive is processed, so that the stores subscribing to that property already have the correct value on page load.

Props westonruter.
Fixes #64649.
Built from https://develop.svn.wordpress.org/trunk@61659


git-svn-id: http://core.svn.wordpress.org/trunk@60970 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/interactivity-api/class-wp-interactivity-api.php

@@ -1314,6 +1314,14 @@ HTML;
 		if ( 'enter' === $mode && ! $this->has_processed_router_region ) {
 			$this->has_processed_router_region = true;
 
+			// Initializes the `state.url` property from the server.
+			$this->state(
+				'core/router',
+				array(
+					'url' => get_self_link(),
+				)
+			);
+
 			// Enqueues as an inline style.
 			wp_register_style( 'wp-interactivity-router-animations', false );
 			wp_add_inline_style( 'wp-interactivity-router-animations', $this->get_router_animation_styles() );

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '7.0-alpha-61658';
+$wp_version = '7.0-alpha-61659';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.