Stop infinit loop on invalid settings css/js file

Don't try to find dirname of false...

Signed-off-by: Joas Schilling <coding@schilljs.com>

lib/private/Template/CSSResourceLocator.php

@@ -62,6 +62,15 @@ class CSSResourceLocator extends ResourceLocator {
 		$style = substr($style, strpos($style, '/')+1);
 		$app_path = \OC_App::getAppPath($app);
 		$app_url = \OC_App::getAppWebPath($app);
+
+		if ($app_path === false && $app_url === false) {
+			$this->logger->error('Could not find resource {resource} to load', [
+				'resource' => $app . '/' . $style . '.css',
+				'app' => 'cssresourceloader',
+			]);
+			return;
+		}
+
 		if(!$this->cacheAndAppendScssIfExist($app_path, $style.'.scss', $app)) {
 			$this->append($app_path, $style.'.css', $app_url);
 		}

lib/private/Template/JSResourceLocator.php

@@ -80,6 +80,15 @@ class JSResourceLocator extends ResourceLocator {
 			$this->appendIfExist($app_path, $script . '.js', $app_url);
 			return;
 		}
+
+		if ($app_path === false && $app_url === false) {
+			$this->logger->error('Could not find resource {resource} to load', [
+				'resource' => $app . '/' . $script . '.js',
+				'app' => 'jsresourceloader',
+			]);
+			return;
+		}
+
 		if (!$this->cacheAndAppendCombineJsonIfExist($app_path, $script.'.json', $app)) {
 			$this->append($app_path, $script . '.js', $app_url);
 		}

lib/private/Template/ResourceLocator.php

@@ -116,6 +116,14 @@ abstract class ResourceLocator {
 	 * @throws ResourceNotFoundException Only thrown when $throw is true and the resource is missing
 	 */
 	protected function append($root, $file, $webRoot = null, $throw = true) {
+
+		if (!is_string($root)) {
+			if ($throw) {
+				throw new ResourceNotFoundException($file, $webRoot);
+			}
+			return;
+		}
+
 		if (!$webRoot) {
 			$tmpRoot = $root;
 			/*