NSURLConnection's sendSynchronousRequest enforces minimum 30 second timeout?

While writing the new Image Downloader (Blocking) QC patch for CoreMelt, I ran into what appears to be a bug in Mac OS X’s NSURLConnection framework – if you construct an NSURLRequest and specify a timeout of less than 30 seconds, it’s ignored when you perform a [NSURLConnection sendSynchronousRequest:returningResponse:error:]. The request takes at least 30 seconds to time out, contrary to what the documentation suggests..

Steps to Reproduce:

  1. Construct an NSURL with an http-based url pointing to a server that is currently offline.
  2. Execute the following code block: 
    NSLog(@"begin");
NSURLRequest *request=[NSURLRequest
    requestWithURL:url
    cachePolicy:NSURLRequestReloadIgnoringCacheData
    timeoutInterval:5.0];
NSData *data=[NSURLConnection
    sendSynchronousRequest:request
    returningResponse:&response
    error:&error];
NSLog(@"end");
  3. Compare the timestamps of “begin” and “end”. though they should presumably differ by 5 seconds, they actually differ by exactly 30 seconds.

Any ideas?

Steve Mokris is a developer at Kosada, Inc.