NSMutableURLRequest body malformed after iOS 8.3 update

Question

Before today's iOS 8.3 update I had my code working right, but after updating server started rejecting requests as it could not find JSON data.

I found that iOS is sending a wrong application/x-www-form-urlencoded text (not properly encoded as it seems a JSON object):

This is what I expected to be sent (and what was sent on 8.2):

As I said, this only happens on iOS 8.3 (I just tried on iOS simulator with 8.2 and it works).

I think the problem is in one of the classes that appear on these lines:

NSData *bodyData = [NSJSONSerialization dataWithJSONObject:requestDict options:0 error:nil];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
request.HTTPBody = bodyData;

I checked Apple documentation and none appears as modified recently.

Is someone suffering the same or knows what can lead to this?

Thanks.

Answer 1

I also have encountered this problem in one application.

It looks like it could be a bug introduced in iOS 8.3. From the official Framework Reference, it is said of the NSURLSessionConfiguration's HTTPAdditionalHeaders property:

This property specifies additional headers that are added to all tasks within sessions based on this configuration. For example, you might set the User-Agent header so that it is automatically included in every request your app makes through sessions based on this configuration.

From what I understand, a Content-Type set in this configuration should be automatically included in every request made through this session, which is no longer the case since 8.3. I've filed a radar.

UPDATE: The radar has been set as 'duplicate' of another so it's more likely a bug.

As Luca pointed out, the work around is to set the Content-Type directly on the request:

[request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];

Source: https://developer.apple.com/library/mac/documentation/Foundation/Reference/NSURLSessionConfiguration_class/#//apple_ref/occ/instp/NSURLSessionConfiguration/HTTPAdditionalHeaders

Answer 2

I put the comment as answer here:

Try to indicate the http method like

[request setHTTPMethod:@"POST"]

and / or, the request length

[request setValue:postLength forHTTPHeaderField:@"Content-Length"]; 

and / or the content type

[request setValue:@"application/<YOUR CONTENT TYPE>"forHTTPHeaderField:@"Content-Type"];