block: Fix backing paths for filenames with colons
path_combine() naturally tries to preserve a protocol prefix. However,
it recognizes such a prefix by scanning for the first colon; which is
different from what path_has_protocol() does: There only is a protocol
prefix if there is a colon before the first slash.
A protocol prefix that is not recognized by path_has_protocol() is none,
and should thus not be taken as one.
Case in point, before this patch:
$ ./qemu-img create -f qcow2 -b backing.qcow2 ./top:image.qcow2
qemu-img: ./top:image.qcow2: Could not open './top:backing.qcow2':
No such file or directory
Afterwards:
$ ./qemu-img create -f qcow2 -b backing.qcow2 ./top:image.qcow2
qemu-img: ./top:image.qcow2: Could not open './backing.qcow2':
No such file or directory
Reported-by: yangyang <yangyang@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20170522195217.12991-2-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/block.c b/block.c
index 50ba264..b72b872 100644
--- a/block.c
+++ b/block.c
@@ -163,11 +163,16 @@
if (path_is_absolute(filename)) {
pstrcpy(dest, dest_size, filename);
} else {
- p = strchr(base_path, ':');
- if (p)
- p++;
- else
- p = base_path;
+ const char *protocol_stripped = NULL;
+
+ if (path_has_protocol(base_path)) {
+ protocol_stripped = strchr(base_path, ':');
+ if (protocol_stripped) {
+ protocol_stripped++;
+ }
+ }
+ p = protocol_stripped ?: base_path;
+
p1 = strrchr(base_path, '/');
#ifdef _WIN32
{