Calling help from a popup help window replaces the popup window with a regular window

[bmag]

Bug reproduction steps:

• 1. start emacs: emacs -Q -l "/path/to/popwin.el"
• 2. paste this content to scratch buffer, and load it with M-x eval-buffer:

(setq popwin:special-display-config '((help-mode :position right)))
(popwin-mode)

• 3. call help: C-h f popwin-mode RET. my window layout is now this:

+----------+----------+
|          |          |
|          |          |
|          |          |
| scratch  | help     |
|          |          |
|          |          |
|          |          |
+----------+----------+

• 4. call help again: C-h f popwin-mode RET. my window layout is now this:

+-----------------------+
|                       |
|     scratch           |
|                       |
+-----------------------+
|                       |
|     help              |
|                       |
+-----------------------+

And pressing C-g doesn't close the help window.

This bug also happens when I press RET on links ("xrefs") inside the help window.

[arunce]

This happens a lot to me. I have coded this temporary solution that bypass some popwin features, without losing its functions:
https://github.com/arunce/emacs-makesure

[rakete]

Same problem here, just found this issue via google wondering how to fix it. Also happens when clicking on 'links' in a help buffer.

@arunce could you explain how your emacs-makesure helps bypass this issue?

Is this possibly emacs 25 related? I just upgraded and I don't think I had that problem with 24.5

[arunce]

@rakete it's mostly a workaround that mitigates some nasty problems between sr-speedbar and popwin, but it works with other windows if you call them with a shortcut.

Like this:
(global-set-key [f4] ( lambda () (interactive) (makesure:it-pops "*shell*" t 'shell)))

"shell" is the window name, t or nil if you want focus or not and the 'shell process/function name which will be called if not active.

Also, it helps with the c-g problem mentioned above.

I'm still using emacs 24.5.

[rakete]

I never figured out how to apply your solution to this particular problem @arunce. But I did come up with my own workaround in the meantime:

(defadvice display-buffer (around display-buffer-prevent-popwin-split last activate)
  (let* ((buffer (ad-get-arg 0)))
    (if (and (string-equal (buffer-name buffer) "*Help*")
                (get-buffer-window buffer))
        (let ((display-buffer-alist nil))
          ad-do-it)
      ad-do-it)))

The problem is that clicking a button in a help buffer erases the help buffer, fills it with new content and then eventually calls display-buffer on that same already displayed buffer. The display-buffer function examines display-buffer-alist for a matching function and finds the popwin:display-buffer-action and calls it, causing the problem described in this issue.

So my workaround works by changing the display-buffer so that it won't be able to call popwin:display-buffer-action on an already displayed help buffer by setting display-buffer-alist to nil, but only for help buffers that are already displayed, and nothing else.

Since display-buffer is a very important function this workaround may cause some unforseen side issues. Handle with care.

[Compro-Prasad]

I don't think @m2ym is actively maintaining this repository.