ao_coreaudio_utils: fix error handling in device listing code

This could sometimes cause crashes in hotplug events. (Apparently in
cases when CoreAudio changes its state asynchronously, or such.)

CA_GET_STR() does not set the string if there was an error, so errors
have to be strictly checked before using it.

1 files changed, 10 insertions, 3 deletions

diff --git a/audio/out/ao_coreaudio_utils.c b/audio/out/ao_coreaudio_utils.c
index f6463a314a..7d14b3f75c 100644
--- a/audio/out/ao_coreaudio_utils.c
+++ b/audio/out/ao_coreaudio_utils.c
@@ -51,7 +51,9 @@ static bool ca_is_output_device(struct ao *ao, AudioDeviceID dev)
     size_t n_buffers;
     AudioBufferList *buffers;
     const ca_scope scope = kAudioDevicePropertyStreamConfiguration;
-    CA_GET_ARY_O(dev, scope, &buffers, &n_buffers);
+    OSStatus err = CA_GET_ARY_O(dev, scope, &buffers, &n_buffers);
+    if (err != noErr)
+        return false;
     talloc_free(buffers);
     return n_buffers > 0;
 }
@@ -71,11 +73,16 @@ void ca_get_device_list(struct ao *ao, struct ao_device_list *list)
         char *name;
         char *desc;
         err = CA_GET_STR(devs[i], kAudioDevicePropertyDeviceUID, &name);
+        if (err != noErr) {
+            MP_VERBOSE(ao, "skipping device %d, which has no UID\n", i);
+            talloc_free(ta_ctx);
+            continue;
+        }
         talloc_steal(ta_ctx, name);
         err = CA_GET_STR(devs[i], kAudioObjectPropertyName, &desc);
-        talloc_steal(ta_ctx, desc);
         if (err != noErr)
-            desc = "Unknown";
+            desc = talloc_strdup(NULL, "Unknown");
+        talloc_steal(ta_ctx, desc);
         ao_device_list_add(list, ao, &(struct ao_device_desc){name, desc});
         talloc_free(ta_ctx);
     }