mixer: Fix missing hctl handle free in snd_mixer_attach_hctl()

Yet another missing piece.

Also, update the function document to warn about the behavior at
error.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/src/mixer/mixer.c b/src/mixer/mixer.c
index eee9875b44fba811fa8b933d8664c5184efbeaf1..3a79c8e91efb0f6c67c0ba365b54eb6f72679d69 100644 (file)
--- a/src/mixer/mixer.c
+++ b/src/mixer/mixer.c
@@ -214,6 +214,8 @@ int snd_mixer_attach(snd_mixer_t *mixer, const char *name)
  * \param mixer Mixer handle
  * \param hctl the HCTL to be attached
  * \return 0 on success otherwise a negative error code
+ *
+ * Upon error, this function closes the given hctl handle automatically.
  */
 int snd_mixer_attach_hctl(snd_mixer_t *mixer, snd_hctl_t *hctl)
 {
@@ -222,8 +224,10 @@ int snd_mixer_attach_hctl(snd_mixer_t *mixer, snd_hctl_t *hctl)
 
        assert(hctl);
        slave = calloc(1, sizeof(*slave));
-       if (slave == NULL)
+       if (slave == NULL) {
+               snd_hctl_close(hctl);
                return -ENOMEM;
+       }
        err = snd_hctl_nonblock(hctl, 1);
        if (err < 0) {
                snd_hctl_close(hctl);