From 3546188a41aa8c231e563ac89af68edd2798323b Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sat, 25 May 2013 15:07:05 +0200
Subject: ao_alsa: always unset ALSA error handler, cleanup on init error

The ALSA device was not closed when initialization failed.

The ALSA error handler (set with snd_lib_error_set_handler()) was not
unset when closing ao_alsa. If this is not done, the handler will still
be called when other libraries using ALSA cause errors, even though
ao_alsa was long closed. Since these messages were prefixed with
"[AO_ALSA]", they were misleading and implying ao_alsa was still used.

For some reason, our error handler is still called even after doing
snd_lib_error_set_handler(NULL), which should be impossible. Checking
with the debuggers, inserting printf(), as well as the alsa-lib source
code all suggest our error handler should not be called, but it still
happens. It's a complete mystery.
---
 audio/out/ao_alsa.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

(limited to 'audio')

diff --git a/audio/out/ao_alsa.c b/audio/out/ao_alsa.c
index d2e8180608..a8952e4547 100644
--- a/audio/out/ao_alsa.c
+++ b/audio/out/ao_alsa.c
@@ -75,6 +75,7 @@ struct priv {
 
 static float get_delay(struct ao *ao);
 static int play(struct ao *ao, void *data, int len, int flags);
+static void uninit(struct ao *ao, bool immed);
 
 static void alsa_error_handler(const char *file, int line, const char *function,
                                int err, const char *format, ...)
@@ -436,14 +437,11 @@ static int init(struct ao *ao, char *params)
     mp_msg(MSGT_AO, MSGL_V,
            "alsa-init: requested format: %d Hz, %d channels, %x\n",
            ao->samplerate, ao->channels.num, ao->format);
-    p->alsa = NULL;
-    mp_msg(MSGT_AO, MSGL_V, "alsa-init: using ALSA %s\n", snd_asoundlib_version());
+
 
     p->prepause_frames = 0;
     p->delay_before_pause = 0;
 
-    snd_lib_error_set_handler(alsa_error_handler);
-
     //subdevice parsing
     // set defaults
     block = 1;
@@ -478,6 +476,9 @@ static int init(struct ao *ao, char *params)
 
     p->can_pause = 1;
 
+    mp_msg(MSGT_AO, MSGL_V, "alsa-init: using ALSA %s\n", snd_asoundlib_version());
+    snd_lib_error_set_handler(alsa_error_handler);
+
     int open_mode = block ? 0 : SND_PCM_NONBLOCK;
     int isac3 =  AF_FORMAT_IS_IEC61937(ao->format);
     //modes = 0, SND_PCM_NONBLOCK, SND_PCM_ASYNC
@@ -626,6 +627,7 @@ static int init(struct ao *ao, char *params)
     return 0;
 
 alsa_error:
+    uninit(ao, true);
     return -1;
 } // end init
 
@@ -644,13 +646,12 @@ static void uninit(struct ao *ao, bool immed)
         err = snd_pcm_close(p->alsa);
         CHECK_ALSA_ERROR("pcm close error");
 
-        p->alsa = NULL;
         mp_msg(MSGT_AO, MSGL_V, "alsa-uninit: pcm closed\n");
-    } else {
-        mp_tmsg(MSGT_AO, MSGL_ERR, "[AO_ALSA] No handler defined!\n");
     }
 
-alsa_error: ;
+alsa_error:
+    p->alsa = NULL;
+    snd_lib_error_set_handler(NULL);
 }
 
 static void audio_pause(struct ao *ao)
-- 
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