Subject: Re: bug#20063: 24.4: read-from-minibuffer improperly setting hist parameter

From: Glenn Morris <[email-masked]>
Date: Sun, 08 Mar 2015 21:08:57 -0400

Boruch Baum wrote:

> Function `toggle-option' calls `completing-read', without providing
> parameters REQUIRE-MATCH or HIST. `completing-read' calls
> `completing-read-default' in `minibuffer.el'. `completing-read-default'
> calls `read-from-minibuffer' in `minibuf.c'. There, on line 974 of
> `minibuf.c:'
>
>      if (NILP (histvar))
>        histvar = Qminibuffer_history;
>
> If I understand this correctly, this says that even if the caller
> explicitly says that there should be no history used (condition nil),
> the Qminibuffer_history should be used anyway.

Nil means use the default history list. Eg see "Minibuffer History" in
the elisp manual:

  If you don't specify HISTORY, then the default history list
  `minibuffer-history' is used.

I don't see a bug here, other than perhaps the doc of completing-read
could stand to be more explicit, like the elisp manual is.