WMR stereo-effect fails when Graphics.CopyTexture is used in OnRenderImage

Hello!

I've faced a bug that easily reproduced.
There is a very simple scene: MainCamera, Canvas with sprite on it, simple MonoBehaviour script attached to MainCamera.
That script implements OnRenderImage method.
In that method I need to copy source RenderTexture to some intermediate Texture2D, do something with that texture and copy back to destination RenderTexture.

Here is the code:

Code (CSharp):

1. private void OnRenderImage(RenderTexture source, RenderTexture destination)
2.     {
3.         if(TestTexture == null)
4.         {
5.             TestTexture = new Texture2D(source.width, source.height, TextureFormat.RGBAHalf, false);
6.         }
7.  
8.         Graphics.CopyTexture(source, TestTexture);
9.         Graphics.Blit(TestTexture, destination);
10.        
11.     }

That code works fine in SteamVR but somehow spoils stereo-effect in WMR. It looks like textures for left and right eyes are being applied with incorrect shifts to render on displays.

I've already reported the bug as (Case 1160871) but I hope there might by some workaround solution.