Magit `zz` (stash both) does not allow whitespace in minibuffer

Question

Sometimes when using command zz (stash both), the minibuffer to enter a stash message does not allow me to enter whitespace (e.g. space chars). I typically resolve to use dashes or underscores or even the tedious C-q SPC, since it is not really important. Yet on other occasions I am sure I have had no problems to enter space chars.

Can someone explain this? Is it a version problem, mine is 20221208.1848.

EDIT: this is embarrassing. The hints in comments and the answer about checking my setup and using describe-key in the minibuffer prompted me to inspect my startup script for emacs, grown over many years. It explicitly defines (local-set-key " " 'minibuffer-complete-word) for the minibuffer. Obviously I have no idea anymore when and why I had the bright idea to enter this.

I don't think this question can help others, as it is probably too specific to serve even as a hint to carefully check startup scripts and try a clean version first. So I will delete it some time soon, giving the contributors time to have a good laugh at my blunder.

Answer 1

Emacs minibuffers for completion, except file-name completion, bind SPC to minibuffer-complete-word. I'm guessing that's the problem here.

Try either (1) globally binding SPC to self-insert-command in, say minibuffer-local-completion-map or (2) doing that only for the zz command. Here's #1:

(define-key minibuffer-local-map (kbd "SPC") 'self-insert-command)

If you want SPC to self-insert only for must-match completion then do that for minibuffer-local-must-match-map instead.

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If, as a comment by @Gilles guesses, the command in question uses a keymap other than a completion keymap -- e.g., if it uses just function read-from-minibuffer, which uses keymap minibuffer-local-map, then just do the same thing I showed above, but with that keymap.

But first, check what the binding of SPC is in that keymap. You can do that with command describe-keymap. If that command is not available in your version of Emacs, you can get it with library help-fns+.el.