Interactivity API: Allow missing state negation on server

Aligns on the behavior of the negation operator with directives to missing paths in client and in server.

With a directive like the following:
{{{
<div data-wp-bind--hidden="!state.missing.property">
	This should be hidden by the <code>hidden</code> attribute.
</div>
}}}

Both server and client will return with this fix:
{{{
<div data-wp-bind--hidden="!state.missing.property" hidden="">
	This should be hidden by the <code>hidden</code> attribute.
</div>
}}}

Props jonsurrell, luisherranz.
Fixes #62374.


Built from https://develop.svn.wordpress.org/trunk@59398


git-svn-id: http://core.svn.wordpress.org/trunk@58784 1a063a9b-81f0-0310-95a4-ce76da25c4cd

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

@@ -584,7 +584,8 @@ final class WP_Interactivity_API {
 			} elseif ( is_object( $current ) && isset( $current->$path_segment ) ) {
 				$current = $current->$path_segment;
 			} else {
-				return null;
+				$current = null;
+				break;
 			}
 
 			if ( $current instanceof Closure ) {

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.8-alpha-59397';
+$wp_version = '6.8-alpha-59398';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.