Commit 0d54a6fe authored by Max Reitz's avatar Max Reitz
Browse files

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: default avataryangyang <yangyang@redhat.com>
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Message-id: 20170522195217.12991-2-mreitz@redhat.com
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent bcb07dba

block.c

+10 −5
Original line number Diff line number Diff line
@@ -163,11 +163,16 @@ void path_combine(char *dest, int dest_size, 
    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

        {