Use getAbsoluteUrl for redirection URL

Also separate the function into getDefaultPageUrl() and
redirectToDefaultPage() to make it testable.

lib/private/util.php

@@ -815,10 +815,13 @@ class OC_Util {
 	}
 
 	/**
-	 * Redirect to the user default page
-	 * @return void
+	 * Returns the URL of the default page
+	 * based on the system configuration and
+	 * the apps visible for the current user
+	 *
+	 * @return string URL
 	 */
-	public static function redirectToDefaultPage() {
+	public static function getDefaultPageUrl() {
 		$urlGenerator = \OC::$server->getURLGenerator();
 		if(isset($_REQUEST['redirect_url'])) {
 			$location = urldecode($_REQUEST['redirect_url']);
@@ -837,11 +840,20 @@ class OC_Util {
 						break;
 					}
 				}
-				$location = $urlGenerator->linkTo($appId, 'index.php');
+				$location = $urlGenerator->getAbsoluteURL('/index.php/apps/' . $appId . '/');
 			}
 		}
+		return $location;
+	}
+
+	/**
+	 * Redirect to the user default page
+	 * @return void
+	 */
+	public static function redirectToDefaultPage() {
+		$location = self::getDefaultPageUrl();
 		OC_Log::write('core', 'redirectToDefaultPage: '.$location, OC_Log::DEBUG);
-		header( 'Location: '.$location );
+		header('Location: '.$location);
 		exit();
 	}