Re: [Qemu-devel] [PATCH v2 2/5] char: Clean up fragile use of error_is_set()

[Eric Blake <eblake@redhat.com>]

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On 05/19/2014 10:57 AM, Markus Armbruster wrote:
> Using error_is_set(ERRP) to find out whether a function failed is
> either wrong, fragile, or unnecessarily opaque.  It's wrong when ERRP
> may be null, because errors go undetected when it is.  It's fragile
> when proving ERRP non-null involves a non-local argument.  Else, it's
> unnecessarily opaque (see commit 84d18f0).
> 
> The error_is_set(errp) in qemu_chr_new_from_opts() is merely fragile,
> because the callers never pass a null errp argument.
> 
> Make the code more robust and more obviously correct: receive the
> error in a local variable, then propagate it through the parameter.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  qemu-char.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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