From 0643cb81c37f54384325fe6caff3ac118affff42 Mon Sep 17 00:00:00 2001
From: DreamPiggy <lizhuoli1126@126.com>
Date: Sat, 23 Jul 2022 21:08:55 +0800
Subject: [PATCH] Fix the rare case when cancel an async disk cache query may
 cause twice callback

One is sync and another is async
---
 SDWebImage/Core/SDImageCache.m | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/SDWebImage/Core/SDImageCache.m b/SDWebImage/Core/SDImageCache.m
index 1dc25feb..cce92f64 100644
--- a/SDWebImage/Core/SDImageCache.m
+++ b/SDWebImage/Core/SDImageCache.m
@@ -662,6 +662,13 @@ static NSString * _defaultDiskCacheDirectory;
             }
             if (doneBlock) {
                 dispatch_async(dispatch_get_main_queue(), ^{
+                    // Dispatch from IO queue to main queue need time, user may call cancel during the dispatch timing
+                    // This check is here to avoid double callback (one is from `SDImageCacheToken` in sync)
+                    @synchronized (operation) {
+                        if (operation.isCancelled) {
+                            return;
+                        }
+                    }
                     doneBlock(diskImage, diskData, SDImageCacheTypeDisk);
                 });
             }