Split goaway to System::externalRedirectTo() and App->internalRedirect()

src/Core/Authentication.php

@@ -194,7 +194,7 @@ class Authentication extends BaseObject
 			Addon::callHooks('logged_in', $a->user);
 
 			if (($a->module !== 'home') && isset($_SESSION['return_url'])) {
-				goaway($a->getbaseUrl() . '/' . $_SESSION['return_url']);
+				$a->internalRedirect($_SESSION['return_url']);
 			}
 		}
 	}

src/Core/System.php

@@ -5,6 +5,7 @@
 namespace Friendica\Core;
 
 use Friendica\BaseObject;
+use Friendica\Network\HTTPException\InternalServerErrorException;
 use Friendica\Util\XML;
 
 /**
@@ -236,6 +237,23 @@ class System extends BaseObject
 		return max($load_arr[0], $load_arr[1]);
 	}
 
+	/**
+	 * Redirects to an external URL (fully qualified URL)
+	 * If you want to route relative to the current Friendica base, use App->internalRedirect()
+	 *
+	 * @param string $url The new Location to redirect
+	 * @throws InternalServerErrorException If the URL is not fully qualified
+	 */
+	public static function externalRedirect($url)
+	{
+		if (!filter_var($url, FILTER_VALIDATE_URL)) {
+			throw new InternalServerErrorException('URL is not a fully qualified URL, please use App->internalRedirect() instead');
+		}
+
+		header("Location: $url");
+		exit();
+	}
+
 	/// @todo Move the following functions from boot.php
 	/*
 	function killme()

src/Core/UserImport.php

@@ -272,6 +272,6 @@ class UserImport
 		Worker::add(PRIORITY_HIGH, 'Notifier', 'relocate', $newuid);
 
 		info(L10n::t("Done. You can now login with your username and password"));
-		$a->redirect('login');
+		$a->internalRedirect('login');
 	}
 }