Connectors: Add registry guards before registering settings and passing keys.

Skip `register_setting` in `_wp_register_default_connector_settings()`
when the AI provider is not in the registry, preventing REST-exposed
settings that silently reject values. Reorder the `hasProvider` check
in `_wp_connectors_pass_default_keys_to_ai_client()` to run before
reading the option. Update the REST settings test to reflect that
connector settings are only registered when their provider is active.

Follow-up to [555bb8a], [bd6c4c8].

See #64791.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gziolo

src/wp-includes/connectors.php

@@ -316,12 +316,19 @@ function _wp_connectors_validate_keys_in_rest( WP_REST_Response $response, WP_RE
  * @access private
  */
 function _wp_register_default_connector_settings(): void {
+	$registry = AiClient::defaultRegistry();
+
 	foreach ( _wp_connectors_get_connector_settings() as $connector_id => $connector_data ) {
 		$auth = $connector_data['authentication'];
 		if ( 'ai_provider' !== $connector_data['type'] || 'api_key' !== $auth['method'] || empty( $auth['setting_name'] ) ) {
 			continue;
 		}
 
+		// Skip registering the setting if the provider is not in the registry.
+		if ( ! $registry->hasProvider( $connector_id ) ) {
+			continue;
+		}
+
 		$setting_name = $auth['setting_name'];
 		register_setting(
 			'connectors',
@@ -375,8 +382,12 @@ function _wp_connectors_pass_default_keys_to_ai_client(): void {
 				continue;
 			}
 
+			if ( ! $registry->hasProvider( $connector_id ) ) {
+				continue;
+			}
+
 			$api_key = _wp_connectors_get_real_api_key( $auth['setting_name'], '_wp_connectors_mask_api_key' );
-			if ( '' === $api_key || ! $registry->hasProvider( $connector_id ) ) {
+			if ( '' === $api_key ) {
 				continue;
 			}
 

tests/phpunit/tests/rest-api/rest-settings-controller.php

@@ -120,10 +120,6 @@ public function test_get_items() {
 			'default_comment_status',
 			'site_icon', // Registered in wp-includes/blocks/site-logo.php
 			'wp_enable_real_time_collaboration',
-			// Connectors API keys are registered in _wp_register_default_connector_settings() in wp-includes/connectors.php.
-			'connectors_ai_anthropic_api_key',
-			'connectors_ai_google_api_key',
-			'connectors_ai_openai_api_key',
 		);
 
 		if ( ! is_multisite() ) {