catching NotPermittedException and throw it to the dav client as 403

lib/connector/sabre/file.php

@@ -78,12 +78,17 @@ class OC_Connector_Sabre_File extends OC_Connector_Sabre_Node implements Sabre_D
 		// mark file as partial while uploading (ignored by the scanner)
 		$partpath = $this->path . '.part';
 
+		try {
 			$putOkay = $fs->file_put_contents($partpath, $data);
 			if ($putOkay === false) {
 				\OC_Log::write('webdav', '\OC\Files\Filesystem::file_put_contents() failed', \OC_Log::ERROR);
 				$fs->unlink($partpath);
+				// because we have no clue about the cause we can only throw back a 500/Internal Server Error
 				throw new Sabre_DAV_Exception();
 			}
+		} catch (\OCP\Files\NotPermittedException $e) {
+			throw new Sabre_DAV_Exception_Forbidden();
+		}
 
 		//detect aborted upload
 		if (isset ($_SERVER['REQUEST_METHOD']) && $_SERVER['REQUEST_METHOD'] === 'PUT' ) {