[pulseaudio-discuss] [PATCH] sink-input: Fix logical error in condition

[Arun Raghavan]

On Wed, 2015-02-25 at 16:42 +0600, Boris Egorov wrote:
> Error: if thread_info.state is DRAINED, it cannot be equal to RUNNING.
> So, part of condition is redundant or wrong. Original code looks
> different from this (see commit 045c1d602dcba578), so it is most likely
> wrong. We need to set thread_info.drained to 1 only if thread_info.state
> is not DRAINED or RUNNING.
> 
> Issue detected by PVS Studio and Cppcheck.
> 
> Signed-off-by: Boris Egorov <egorov at linux.com>
> ---
>  src/pulsecore/sink-input.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/pulsecore/sink-input.c b/src/pulsecore/sink-input.c
> index d95a93e..29beca6 100644
> --- a/src/pulsecore/sink-input.c
> +++ b/src/pulsecore/sink-input.c
> @@ -1876,7 +1876,7 @@ void pa_sink_input_set_state_within_thread(pa_sink_input *i, pa_sink_input_state
>          return;
>  
>      if ((state == PA_SINK_INPUT_DRAINED || state == PA_SINK_INPUT_RUNNING) &&
> -        !(i->thread_info.state == PA_SINK_INPUT_DRAINED || i->thread_info.state != PA_SINK_INPUT_RUNNING))
> +        !(i->thread_info.state == PA_SINK_INPUT_DRAINED || i->thread_info.state == PA_SINK_INPUT_RUNNING))
>          pa_atomic_store(&i->thread_info.drained, 1);
>  
>      corking = state == PA_SINK_INPUT_CORKED && i->thread_info.state == PA_SINK_INPUT_RUNNING;

This fix looks correct to me, but I'm wondering why it's never triggered
a bug (or whether we can fashion a test case that should trigger it).

-- Arun