@-name rewrites: don't redirect to slashed version (#1447)

Author: mattwiebe

.github/changelog/fix-@-name-unslashed-redirects

@@ -0,0 +1,4 @@
+Significance: patch
+Type: changed
+
+Don't redirect @-name URLs to trailing slashed versions

includes/class-activitypub.php

@@ -26,6 +26,7 @@ public static function init() {
 		\add_filter( 'template_include', array( self::class, 'render_activitypub_template' ), 99 );
 		\add_action( 'template_redirect', array( self::class, 'template_redirect' ) );
 		\add_filter( 'redirect_canonical', array( self::class, 'redirect_canonical' ), 10, 2 );
+		\add_filter( 'redirect_canonical', array( self::class, 'no_trailing_redirect' ), 10, 2 );
 		\add_filter( 'query_vars', array( self::class, 'add_query_vars' ) );
 		\add_filter( 'pre_get_avatar_data', array( self::class, 'pre_get_avatar_data' ), 11, 2 );
 
@@ -209,6 +210,22 @@ function () use ( $id ) {
 		);
 	}
 
+	/**
+	 * Remove trailing slash from ActivityPub @username requests.
+	 *
+	 * @param string $redirect_url  The URL to redirect to.
+	 * @param string $requested_url The requested URL.
+	 *
+	 * @return string $redirect_url The possibly-unslashed redirect URL.
+	 */
+	public static function no_trailing_redirect( $redirect_url, $requested_url ) {
+		if ( get_query_var( 'actor' ) ) {
+			return $requested_url;
+		}
+
+		return $redirect_url;
+	}
+
 	/**
 	 * Add support for `p` and `author` query vars.
 	 *

tests/includes/class-test-activitypub.php

@@ -219,4 +219,30 @@ public function test_custom_post_type_with_support_returns_200() {
 		unset( $_SERVER['HTTP_ACCEPT'] );
 		_unregister_post_type( 'test_cpt_supported' );
 	}
+
+	/**
+	 * Test no_trailing_redirect method.
+	 *
+	 * @covers ::no_trailing_redirect
+	 */
+	public function test_no_trailing_redirect() {
+		// Test case 1: When actor query var is set, it should return the requested URL.
+		set_query_var( 'actor', 'testuser' );
+		$requested_url = 'https://example.org/@testuser';
+		$redirect_url  = 'https://example.org/@testuser/';
+
+		$result = \Activitypub\Activitypub::no_trailing_redirect( $redirect_url, $requested_url );
+		$this->assertEquals( $requested_url, $result, 'Should return requested URL when actor query var is set.' );
+
+		// Test case 2: When actor query var is not set, it should return the redirect URL.
+		set_query_var( 'actor', '' );
+		$requested_url = 'https://example.org/some-page';
+		$redirect_url  = 'https://example.org/some-page/';
+
+		$result = \Activitypub\Activitypub::no_trailing_redirect( $redirect_url, $requested_url );
+		$this->assertEquals( $redirect_url, $result, 'Should return redirect URL when actor query var is not set.' );
+
+		// Clean up.
+		set_query_var( 'actor', null );
+	}
 }