From c948484c7fe764467ee749aa04d02617d8fee591 Mon Sep 17 00:00:00 2001
From: Ilya Konstantinov <ilya.konstantinov@gmail.com>
Date: Thu, 7 May 2015 21:18:27 +0200
Subject: [PATCH] avfvideosrc: fix unconditional buffer queue unlock

Unless stopRequest is set, we should unlock conditionally -- otherwise,
the 'create:' method can wake up to an empty buffer queue
and pull a nil buffer.

https://bugzilla.gnome.org/show_bug.cgi?id=748054
---
 sys/applemedia/avfvideosrc.m | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/applemedia/avfvideosrc.m b/sys/applemedia/avfvideosrc.m
index 176502adbc..00f5c65242 100644
--- a/sys/applemedia/avfvideosrc.m
+++ b/sys/applemedia/avfvideosrc.m
@@ -824,7 +824,7 @@ didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
 {
   [bufQueueLock lock];
   stopRequest = NO;
-  [bufQueueLock unlock];
+  [bufQueueLock unlockWithCondition:([bufQueue count] == 0) ? NO_BUFFERS : HAS_BUFFER_OR_STOP_REQUEST];
 
   return YES;
 }
@@ -862,7 +862,7 @@ didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
   [self getSampleBuffer:sampleBuffer timestamp:&timestamp duration:&duration];
 
   if (timestamp == GST_CLOCK_TIME_NONE) {
-    [bufQueueLock unlock];
+    [bufQueueLock unlockWithCondition:([bufQueue count] == 0) ? NO_BUFFERS : HAS_BUFFER_OR_STOP_REQUEST];
     return;
   }