qemu-img: abort when full_backing_filename not present

...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 <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1450122916-4706-5-git-send-email-jsnow@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/qemu-img.c b/qemu-img.c
index b6b4c9e3046d269b088923768cd83d8f99cbffad..3d48b4f00e00e098cd728d363842c54e6f426f16 100644 (file)
--- 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;