Fixed bug where ASVideoNodeDelegate error reporting callback would cr…

…ash an app because of not responding to selector;

refs TextureGroup#291

Source/ASVideoNode.mm

@@ -58,6 +58,7 @@ @interface ASVideoNode ()
     unsigned int delegateVideoNodeDidSetCurrentItem:1;
     unsigned int delegateVideoNodeDidStallAtTimeInterval:1;
     unsigned int delegateVideoNodeDidRecoverFromStall:1;
+    unsigned int delegateVideoNodeDidFailToLoadValuesForKey:1;
   } _delegateFlags;
 
   BOOL _shouldBePlaying;
@@ -153,7 +154,9 @@ - (void)prepareToPlayAsset:(AVAsset *)asset withKeys:(NSArray<NSString *> *)requ
     AVKeyValueStatus keyStatus = [asset statusOfValueForKey:key error:&error];
     if (keyStatus == AVKeyValueStatusFailed) {
       NSLog(@"Asset loading failed with error: %@", error);
-      [self.delegate videoNode:self didFailToLoadValueForKey:key asset:asset error:error];
+      if (_delegateFlags.delegateVideoNodeDidFailToLoadValuesForKey) {
+        [self.delegate videoNode:self didFailToLoadValueForKey:key asset:asset error:error];
+      }
     }
   }
 
@@ -604,6 +607,7 @@ - (void)setDelegate:(id<ASVideoNodeDelegate>)delegate
     _delegateFlags.delegateVideoNodeDidSetCurrentItem = [delegate respondsToSelector:@selector(videoNode:didSetCurrentItem:)];
     _delegateFlags.delegateVideoNodeDidStallAtTimeInterval = [delegate respondsToSelector:@selector(videoNode:didStallAtTimeInterval:)];
     _delegateFlags.delegateVideoNodeDidRecoverFromStall = [delegate respondsToSelector:@selector(videoNodeDidRecoverFromStall:)];
+    _delegateFlags.delegateVideoNodeDidFailToLoadValuesForKey = [delegate respondsToSelector:@selector(videoNode:didFailToLoadValueForKey:asset:error:)];
   }
 }