An attempt to obtain www.responseHeaders cauzes exception

Hi all.
I recently updated my project to unity 2017.1.0p5 and meat strange behaviour.
When i load local file using WWW class and then try to check responseHeaders property of WWW class instance. It throws exception:

ERROR:

Code (CSharp):

1. NullReferenceException: Object reference not set to an instance of an object
2. UnityEngine.WWW.get_responseHeaders () (at C:/buildslave/unity/build/Runtime/WebRequestWWW/UWRWWW.cs:158)
3. TestLocalLoading+<LoadLocalFile>c__Iterator0.MoveNext () (at Assets/Scripts/TestLocalLoading.cs:20)
4. UnityEngine.SetupCoroutine.InvokeMoveNext (IEnumerator enumerator, IntPtr returnValueAddress) (at C:/buildslave/unity/build/Runtime/Export/Coroutines.cs:17)

SAMPLE CODE:

Code (CSharp):

1. public class TestLocalLoading : MonoBehaviour
2. {
3.     public void TesLoacalLoading()
4.     {
5.         StartCoroutine(LoadLocalFile());
6.     }
7.  
8.     private static IEnumerator LoadLocalFile()
9.     {
10.         var filePath = "file://" + Application.dataPath + "/TestLocalLoading.txt";
11.         var www = new WWW(filePath);
12.  
13.         while (!www.isDone)
14.             yield return www;
15.  
16.         Debug.LogFormat("www.text: {0}", www.text); // file loaded correctly
17.         Debug.LogFormat("www.responseHeaders: {0}", www.responseHeaders); // this line produce exception
18.     }
19. }

It's just a simple code to reproduce error.
In Unity 5.3.4p1 all was fine. But since WWW became a wrapper for UnityWebRequest I start getting errors.

 

I'm having the exact same problem with Unity 2017.1.1p3, the previous version 5.4.1p1 that I used doesn't have this problem. I believe this is a bug in the responseHeaders getter. @sergey-samus since you've already have a simple repro, could you please report a bug so that the Unity team can get it fixed?

 

Is there any patch build that contains a fix for this? Thanks.

 

There's a different issue here as well. In the case reported by sergey, WWW.responseHeaders does not return null, trying to access it throws an exception.

As far as I can tell, accessing WWW.responseHeaders will throw a NullReferenceException if the response body is empty, even if there are response headers.

 

We're interested in these fixes as well, thank you

 

We need it too.

 

I'm also interested in a timeline for a fix. This has broken our plugin for all our customers that upgrade to 2017.X.

We tried UnityWebRequest (https://docs.unity3d.com/ScriptReference/Networking.UnityWebRequest.html) and after a quick test here it doesn't seem to have the same problems obtaining headers.