Re: [Qemu-devel] [PATCH trivial v2] block.c: Add return value for bdrv_append_temp_snapshot() to avoid incorrect failure processing issue

[Kevin Wolf <kwolf@redhat.com>]

Am 23.06.2014 um 17:28 hat Chen Gang geschrieben:
> When failure occurs, 'ret' need be set, or may return 0 to indicate success.
> And error_propagate() also need be called only one time within a function.
> 
> It is abnormal to prevent bdrv_append_temp_snapshot() return value but still
> set errp when error occurs -- although it contents return value internally.
> 
> So let bdrv_append_temp_snapshot() internal return value outside, and let
> all things normal, then fix the issue too.
> 
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>

What does this fix?

Having both a return value and an Error* object is duplication and
only a sign that a function hasn't been fully converted to the Error
framework yet. We shouldn't introduce new instances of this without a
very good reason.

Kevin