It's not an issue anymore when switching to Airplane, but still can reproduce the issue when throttling on Charles proxy.
I ended up with this solution (checking if connection:didWriteData:...
is telling the truth in connectionDidFinishDownloading:destinationURL:
):
- (void)connection:(NSURLConnection *)connection didWriteData:(long long)bytesWritten totalBytesWritten:(long long)totalBytesWritten expectedTotalBytes:(long long)expectedTotalBytes
{
...
self.declaredSizeOfDownloadedFile = expectedTotalBytes;
}
And:
- (void)connectionDidFinishDownloading:(NSURLConnection *)connection destinationURL:(NSURL *) destinationURL
{
NSDictionary* fileAttributes = [[NSFileManager defaultManager] attributesOfItemAtPath:destinationURL.absoluteString error:nil];
NSNumber* destinationFileSize = [fileAttributes objectForKey:NSFileSize];
if (destinationFileSize.intValue != self.declaredSizeOfDownloadedFile)
{
NSError* error = ...;
[self connection:connection didFailWithError:error];
self.declaredSizeOfDownloadedFile = 0;
return;
}
...
}