Fix uninitialized frame crashes

[gcv]

No description provided.

[zenspider]

Can you 'splain how you get this to occur? I don't hit this ever.

[gcv]

Start from a fresh Emacs instance. Make sure you don't have this patch or #86 loaded.

Evaluate:

(let ((after-make-frame-functions nil))
  (make-frame))

This pops open a new frame. Perspective is not enabled in this frame, and will break if you attempt to use it. This is expected behavior (although far from ideal), as after-make-frame-functions bound to nil suppresses the hooks which handle the creation of all frame parameters which perspective relies on.

Unfortunately, this also breaks perspective in the original frame in which all frame parameters are properly loaded. Keep the new frame open, go back to the original frame, make a new perspective, and then attempt to kill that new perspective. You'll get Wrong type argument: hash-table-p, nil.

This matters because posframe does exactly this when creating its frames. posframe-dependent packages create hidden frames, none of which have the necessary frame parameter initialization. Most notably, this breaks ivy-posframe. To add insult to injury, this is not debuggable with toggle-debug-on-error.

I wrote a test, but I can't get it to work properly in terminal mode Emacs: calling make-frame in a batch test run errors out with "Unknown terminal type".

(ert-deftest issue-104-errors-with-uninitialized-frames ()
  (persp-test-with-persp
   ;;(persp-switch "A")
   (let ((after-make-frame-functions nil))
     (let ((orig-frame (selected-frame))
           (new-frame (make-frame)))
       (with-selected-frame orig-frame
         (persp-switch "A")
         (persp-switch "main")
         ;; should not error out:
         (persp-kill "test"))))))

This PR is an alternative to #86, which — as you noted — is a much more invasive approach to solving this problem. (It also complements the overall cleanup of frame parameter use in #91, which I haven't had time to test.)

[gcv]

@zenspider: Any thoughts on this?

[zenspider]

no thoughts. just merged. :P