[libvirt] [PATCH 03/30] storagefile: qcow1: Fix check for empty backing file

[Cole Robinson]

>From f772b3d91fd the intention of this code seems to be to set
format=NONE when the image does not have a backing file. However
'buf' here is the whole qcow1 file header. What we want to be
checking is 'res' which is the parsed backing file path.
qcowXGetBackingStore sets this to NULL when there's no backing file.

Signed-off-by: Cole Robinson <crobinso at redhat.com>
---
 src/util/virstoragefile.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 1549067c48..016c8f0799 100644
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -578,7 +578,7 @@ qcow1GetBackingStore(char **res,
      * used to store backing format */
     *format = VIR_STORAGE_FILE_AUTO;
     ret = qcowXGetBackingStore(res, NULL, buf, buf_size, false);
-    if (ret == BACKING_STORE_OK && *buf == '\0')
+    if (ret == BACKING_STORE_OK && !*res)
         *format = VIR_STORAGE_FILE_NONE;
     return ret;
 }
-- 
2.23.0