From 40d3a1de7ab51ba9d113422a6e8e86ccc3f2d0cd Mon Sep 17 00:00:00 2001
From: Garrett Moon <garrett@excitedpixel.com>
Date: Wed, 1 Mar 2017 19:51:16 -0800
Subject: [PATCH] Trying to set the progress block with a nil identifire
 doesn't make sense. (#3117)

---
 Source/ASNetworkImageNode.mm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Source/ASNetworkImageNode.mm b/Source/ASNetworkImageNode.mm
index e151fa406a..40e4bbf5b8 100755
--- a/Source/ASNetworkImageNode.mm
+++ b/Source/ASNetworkImageNode.mm
@@ -439,7 +439,9 @@ static const CGSize kMinReleaseImageOnBackgroundSize = {20.0, 20.0};
   if (clearAndReattempt) {
     // In this case another thread changed the _downloadIdentifierForProgressBlock before we finished registering
     // the new progress block for newDownloadIDForProgressBlock ID. Let's clear it now and reattempt to register
-    [_downloader setProgressImageBlock:nil callbackQueue:dispatch_get_main_queue() withDownloadIdentifier:newDownloadIDForProgressBlock];
+    if (newDownloadIDForProgressBlock) {
+      [_downloader setProgressImageBlock:nil callbackQueue:dispatch_get_main_queue() withDownloadIdentifier:newDownloadIDForProgressBlock];
+    }
     [self _updateProgressImageBlockOnDownloaderIfNeeded];
   }
 }