From e75f3268a43aa6bc31a1d4a05ff6d38be3995d5f Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian.jackson@eu.citrix.com>
Date: Mon, 20 Apr 2009 17:55:20 +0100
Subject: [PATCH] fix qcow2 backing file open

Make `:'-less BDRV_O_FILE bdrv_open2 work again.
qcow2 opens its backing file this way.  Thanks to Yang Zhang for the patch.

Signed-off-by: Yang Zhang <yang.zhang@intel.com>
---
 block.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block.c b/block.c
index 8a0e8b282..36f5eb919 100644
--- a/block.c
+++ b/block.c
@@ -405,6 +405,8 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
     pstrcpy(bs->filename, sizeof(bs->filename), filename);
     if (flags & BDRV_O_FILE) {
         drv = find_protocol(filename);
+        if (!drv)
+            drv = &bdrv_raw;
     } else if (!drv) {
         drv = find_image_format(filename);
     }
-- 
2.39.5