From 895005f4df9bf94c277e60e4c7698cd5ccb3605d Mon Sep 17 00:00:00 2001
From: Frank Morgner <morgner@informatik.hu-berlin.de>
Date: Wed, 14 Oct 2015 22:28:49 +0200
Subject: [PATCH] added error checking

---
 src/libopensc/cwa-dnie.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libopensc/cwa-dnie.c b/src/libopensc/cwa-dnie.c
index 68a15a3f..28cbe64e 100644
--- a/src/libopensc/cwa-dnie.c
+++ b/src/libopensc/cwa-dnie.c
@@ -225,7 +225,7 @@ int dnie_read_file(sc_card_t * card,
 		LOG_FUNC_RETURN(ctx, SC_ERROR_INVALID_ARGUMENTS);
 	/* select file by mean of iso7816 ops */
 	res = card->ops->select_file(card, path, file);
-	if (res != SC_SUCCESS) {
+	if (res != SC_SUCCESS || !file || !(*file)) {
 		msg = "select_file failed";
 		goto dnie_read_file_err;
 	}