[alsa-devel] [PATCH] alsa-lib: snd_device_name_hint misbehaving

[John Lindgren]

On Mon, 2009-11-02 at 14:08 +0100, Takashi Iwai wrote:
> > * Remove erroneous snd_config_delete calls that cause later calls to
> > snd_pcm_open to fail.
> 
> This is bad indeed.  Could you make a small test case to reproduce the
> problem more easily?

Sure.

------

#include <stdio.h>
#include <alsa/asoundlib.h>

void try_open (const char * pcm)
{
    snd_pcm_t * handle;
    int error;

    error = snd_pcm_open (& handle, pcm, SND_PCM_STREAM_PLAYBACK, 0);

    if (error < 0)
        printf ("Failed to open %s: %s.\n", pcm, snd_strerror (error));
    else
    {
        printf ("Opened %s.\n", pcm);
        snd_pcm_close (handle);
    }
}

int main (void)
{
    void * * hints;

    try_open ("default");
    try_open ("front");
    try_open ("pulse");
    try_open ("default");
    try_open ("front");
    try_open ("pulse");

    printf ("Calling snd_device_name_hint().\n");
    snd_device_name_hint (-1, "pcm", & hints);
    snd_device_name_free_hint (hints);

    try_open ("default");
    try_open ("front");
    try_open ("pulse");
    try_open ("default");
    try_open ("front");
    try_open ("pulse");

    return 0;
}

------

$ ./pcmtest
Opened default.
Opened front.
Opened pulse.
Opened default.
Opened front.
Opened pulse.
Calling snd_device_name_hint().
Opened default.
ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front
Failed to open front: No such file or directory.
ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM pulse
Failed to open pulse: No such file or directory.
Opened default.
ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front
Failed to open front: No such file or directory.
ALSA lib pcm.c:2211:(snd_pcm_open_noupdate) Unknown PCM pulse
Failed to open pulse: No such file or directory.