#1807 - #1821 - Fixing incorrectly retained pointer to self which appears to cre…

…ate a dangled pointer

@@ -169,8 +169,9 @@ typedef NSMutableDictionary<NSString *, id> SDCallbacksDictionary;
         for (SDWebImageDownloaderProgressBlock progressBlock in [self callbacksForKey:kProgressCallbackKey]) {
             progressBlock(0, NSURLResponseUnknownLength, self.request.URL);
         }
+        __weak typeof(self) weakSelf = self;
         dispatch_async(dispatch_get_main_queue(), ^{
-            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStartNotification object:self];
+            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStartNotification object:weakSelf];
         });
     } else {
         [self callCompletionBlocksWithError:[NSError errorWithDomain:NSURLErrorDomain code:0 userInfo:@{NSLocalizedDescriptionKey : @"Connection can't be initialized"}]];
@@ -201,8 +202,9 @@ typedef NSMutableDictionary<NSString *, id> SDCallbacksDictionary;
 
     if (self.dataTask) {
         [self.dataTask cancel];
+        __weak typeof(self) weakSelf = self;
         dispatch_async(dispatch_get_main_queue(), ^{
-            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:self];
+            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:weakSelf];
         });
 
         // As we cancelled the connection, its callback won't be called and thus won't
@@ -266,8 +268,9 @@ didReceiveResponse:(NSURLResponse *)response
         
         self.imageData = [[NSMutableData alloc] initWithCapacity:expected];
         self.response = response;
+        __weak typeof(self) weakSelf = self;
         dispatch_async(dispatch_get_main_queue(), ^{
-            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadReceiveResponseNotification object:self];
+            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadReceiveResponseNotification object:weakSelf];
         });
     }
     else {
@@ -280,8 +283,9 @@ didReceiveResponse:(NSURLResponse *)response
         } else {
             [self.dataTask cancel];
         }
+        __weak typeof(self) weakSelf = self;
         dispatch_async(dispatch_get_main_queue(), ^{
-            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:self];
+            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:weakSelf];
         });
         
         [self callCompletionBlocksWithError:[NSError errorWithDomain:NSURLErrorDomain code:((NSHTTPURLResponse *)response).statusCode userInfo:nil]];
@@ -402,10 +406,11 @@ didReceiveResponse:(NSURLResponse *)response
 - (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error {
     @synchronized(self) {
         self.dataTask = nil;
+        __weak typeof(self) weakSelf = self;
         dispatch_async(dispatch_get_main_queue(), ^{
-            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:self];
+            [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadStopNotification object:weakSelf];
             if (!error) {
-                [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadFinishNotification object:self];
+                [[NSNotificationCenter defaultCenter] postNotificationName:SDWebImageDownloadFinishNotification object:weakSelf];
             }
         });
     }