Replace pings_open filter with pre_trackback_post hook

The global pings_open filter suppressed the X-Pingback header which
wp_install_maybe_enable_pretty_permalinks() uses to verify rewrite
rules, breaking pretty permalinks on fresh non-production installs.

Use pre_trackback_post action to reject incoming trackbacks instead,
which only affects the wp-trackback.php entry point. Reverts the
pingsOpen and sendHeaders test changes since pings_open is no longer
filtered.

Author: arcangelini

src/wp-includes/comment.php

@@ -3212,21 +3212,23 @@ function wp_disable_outgoing_pings_for_environment() {
 }
 
 /**
- * Closes pings for posts in non-production environments.
+ * Rejects incoming trackbacks in non-production environments.
+ *
+ * Hooked to `pre_trackback_post` which fires before the trackback is processed.
+ * Sends an error response and exits if pings are disabled for the environment.
  *
  * @since 6.9.0
  * @access private
  *
- * @param bool $pings_open Whether the post is open for pings.
- * @param int  $post_id    The post ID.
- * @return bool False if pings are disabled for the environment, otherwise the original value.
+ * @param int    $post_id       Post ID related to the trackback.
+ * @param string $trackback_url Trackback URL.
  */
-function wp_disable_pings_open_for_environment( $pings_open, $post_id ) {
+function wp_disable_trackback_for_environment( $post_id, $trackback_url ) {
 	if ( wp_should_disable_pings_for_environment() ) {
-		return false;
+		if ( function_exists( 'trackback_response' ) ) {
+			trackback_response( 1, __( 'Sorry, trackbacks are closed for this item.' ) );
+		}
 	}
-
-	return $pings_open;
 }
 
 /**

src/wp-includes/default-filters.php

@@ -424,7 +424,7 @@
 
 // Disable pings (pingbacks, trackbacks, and ping service notifications) in non-production environments.
 add_action( 'do_all_pings', 'wp_disable_outgoing_pings_for_environment', 1, 0 );
-add_filter( 'pings_open', 'wp_disable_pings_open_for_environment', 10, 2 );
+add_action( 'pre_trackback_post', 'wp_disable_trackback_for_environment', 10, 2 );
 add_filter( 'xmlrpc_methods', 'wp_disable_xmlrpc_pingback_for_environment' );
 
 add_action( 'do_robots', 'do_robots' );

tests/phpunit/tests/comment/disablePingsForEnvironment.php

@@ -6,7 +6,7 @@
  * @group comment
  * @covers ::wp_should_disable_pings_for_environment
  * @covers ::wp_disable_outgoing_pings_for_environment
- * @covers ::wp_disable_pings_open_for_environment
+ * @covers ::wp_disable_trackback_for_environment
  * @covers ::wp_disable_xmlrpc_pingback_for_environment
  *
  * @ticket 64837
@@ -182,27 +182,21 @@ public function test_outgoing_pings_preserved_in_production() {
 	/**
 	 * @ticket 64837
 	 */
-	public function test_pings_open_returns_false_in_non_production() {
-		putenv( 'WP_ENVIRONMENT_TYPE=local' );
-
-		$post = self::factory()->post->create_and_get(
-			array( 'ping_status' => 'open' )
-		);
-
-		$this->assertFalse( wp_disable_pings_open_for_environment( true, $post->ID ) );
+	public function test_trackback_hook_registered_in_non_production() {
+		$this->assertSame( 10, has_action( 'pre_trackback_post', 'wp_disable_trackback_for_environment' ) );
 	}
 
 	/**
 	 * @ticket 64837
 	 */
-	public function test_pings_open_unchanged_in_production() {
-		putenv( 'WP_ENVIRONMENT_TYPE=production' );
+	public function test_pings_open_unaffected_by_environment() {
+		putenv( 'WP_ENVIRONMENT_TYPE=local' );
 
 		$post = self::factory()->post->create_and_get(
 			array( 'ping_status' => 'open' )
 		);
 
-		$this->assertTrue( wp_disable_pings_open_for_environment( true, $post->ID ) );
+		$this->assertTrue( pings_open( $post ) );
 	}
 
 	/**

tests/phpunit/tests/comment/pingsOpen.php

@@ -6,13 +6,6 @@
  */
 class Tests_Comment_PingsOpen extends WP_UnitTestCase {
 
-	public function set_up() {
-		parent::set_up();
-
-		// Remove the environment-based filter to test core pings_open() behavior in isolation.
-		remove_filter( 'pings_open', 'wp_disable_pings_open_for_environment' );
-	}
-
 	/**
 	 * @ticket 54159
 	 */

tests/phpunit/tests/wp/sendHeaders.php

@@ -8,13 +8,6 @@
 class Tests_WP_SendHeaders extends WP_UnitTestCase {
 	protected $headers_sent = array();
 
-	public function set_up() {
-		parent::set_up();
-
-		// Remove the environment-based filter to test core behavior in isolation.
-		remove_filter( 'pings_open', 'wp_disable_pings_open_for_environment' );
-	}
-
 	/**
 	 * @ticket 56068
 	 */