If Win32Window::activate() fails, a crash may follow

[marcusl]

If no gl-context is available for thread, the glGetString(GL_EXTENSIONS) returns null, which isn't handled correctly.

The right way would be to check if activate() succeeds and not try to render if it doesn't, something like the following (without calling activate twice)

  m_win->activate();

  if (wglGetCurrentContext()) {

        m_win->render(m_action);

  } 

I get this when I try to render from a different thread than what I created the window in. (I'm working on the actual cause for this, noticing the brittle error handling in the process.)

[dirk]

To fix this activate would have to be able to detect whether it failed and return it's status. Also the whole needs to be able to handle the case that no context is active.

This is too much for 1.8, IMHO. I'll move it 2.0 and we can look at it again.