[Qemu-block] [PATCH v2 3/4] qemu-img: abort when full_backing_filename not present

[John Snow]

...But only if we have the backing_filename. It means something Scary
happened and we can't really be quite exactly sure if we can trust the
backing_filename.

Signed-off-by: John Snow <js...@redhat.com>
---
 qemu-img.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/qemu-img.c b/qemu-img.c
index 033011c..272bb0b 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -2040,7 +2040,10 @@ static ImageInfoList *collect_image_info_list(const char 
*filename,
             if (info->has_full_backing_filename) {
                 filename = info->full_backing_filename;
             } else if (info->has_backing_filename) {
-                filename = info->backing_filename;
+                error_report("Could not determine absolute backing filename,"
+                             " but backing filename '%s' present",
+                             info->backing_filename);
+                goto err;
             }
             if (info->has_backing_filename_format) {
                 fmt = info->backing_filename_format;
-- 
2.4.3