[libvirt] [PATCH] qemu: ignore failure of qemu -M ? on older qemu

[Laine Stump]

On 02/14/2011 03:02 PM, Eric Blake wrote:
> https://bugzilla.redhat.com/show_bug.cgi?id=676563
>
> Regression introduced in commit 2211518.
>
> * src/qemu/qemu_capabilities.c (qemuCapsProbeMachineTypes): Allow
> non-zero exit status.
> ---
>   src/qemu/qemu_capabilities.c |    4 +++-
>   1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
> index ca7d842..cc5552c 100644
> --- a/src/qemu/qemu_capabilities.c
> +++ b/src/qemu/qemu_capabilities.c
> @@ -171,6 +171,7 @@ qemuCapsProbeMachineTypes(const char *binary,
>       char *output;
>       int ret = -1;
>       virCommandPtr cmd;
> +    int status;
>
>       /* Make sure the binary we are about to try exec'ing exists.
>        * Technically we could catch the exec() failure, but that's
> @@ -186,7 +187,8 @@ qemuCapsProbeMachineTypes(const char *binary,
>       virCommandSetOutputBuffer(cmd,&output);
>       virCommandClearCaps(cmd);
>
> -    if (virCommandRun(cmd, NULL)<  0)
> +    /* Ignore failure from older qemu that did not understand '-M ?'.  */
> +    if (virCommandRun(cmd,&status)<  0)
>           goto cleanup;
>
>       if (qemuCapsParseMachineTypesStr(output, machines, nmachines)<  0)

ACK. The older code printed a warning on non-zero exit, but didn't fail, 
so this is proper.