[PATCH 2/2] qemu_migration: Don't mangle NBD part of migration cookie

[Peter Krempa]

On Mon, Oct 26, 2020 at 11:41:36 +0100, Michal Privoznik wrote:
> In recent commit v6.8.0-135-g518be41aaa the formatting of NBD
> into migration cookie was moved into a separate function and with
> it it was switched from direct printing into the output buffer to
> virXMLFormatElement(). But there was a typo. The
> virXMLFormatElement() accepts two buffers on input, one for
> element attributes and another for child elements. Well, the line
> that was supposed to add NBD port into the attributes buffer
> printed the attribute directly into the output buffer which
> produced this mangled XML:
> 
> <qemu-migration>
>    port='49153'<nbd>
>     <disk target='vda' capacity='8589934592'/>
>     <disk target='vdb' capacity='12746752000'/>
>   </nbd>
> </qemu-migration>
> 
> Changing the incriminated line to print into the attributes
> buffer fixes the problem.
> 
> Fixes: 518be41aaa3ebaac5f2307f268d24dc1b40b6b5c
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/qemu/qemu_migration_cookie.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Oops! I'm planning on adding tests for the qemu-migration cookie XML
since we don't have any and it would prevent this problem.

Reviewed-by: Peter Krempa <pkrempa at redhat.com>