GNU bug report logs - #76748
31.0.50; `unload-feature' unbinds NEW-ALIAS and BASE-VARIABLE of variable alias

Previous Next

Full log

View this message in rfc822 format

From: Jens Schmidt <jschmidt4gnu <at> vodafonemail.de>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: Eli Zaretskii <eliz <at> gnu.org>, 76748 <at> debbugs.gnu.org
Subject: bug#76748: 31.0.50; `unload-feature' unbinds NEW-ALIAS and BASE-VARIABLE of variable alias
Date: Wed, 12 Mar 2025 21:36:40 +0100

On 2025-03-05  13:33, Eli Zaretskii wrote:
>> Date: Tue, 04 Mar 2025 21:57:18 +0100
>> From:  Jens Schmidt via "Bug reports for GNU Emacs,
>>  the Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org>
>>
>> 1. `defalias' on builtin variable, like in vhdl-mode.el:
>>
>>      ./progmodes/vhdl-mode.el:2331:  (defvaralias 'vhdl-last-input-event 'last-input-event)
>>
>>    Start with "emacs -Q", then execute with C-j in *scratch*:
>>
>>      (require 'vhdl-mode)
>>      vhdl-mode
>>
>>      (unload-feature 'vhdl-mode)
>>      =>
>>      Lisp error: (error "Built-in variables may not be unbound")
>>        makunbound(vhdl-last-input-event)
>>        #f(compiled-function (x) #<bytecode -0x15f00789bdf1ec4b>)(vhdl-last-input-event)
>>        apply(#f(compiled-function (x) #<bytecode -0x15f00789bdf1ec4b>) vhdl-last-input-event nil)
>>        loadhist-unload-element(vhdl-last-input-event)
>>        unload-feature(vhdl-mode)
>>
>> 2. `define-obsolete-variable-alias' on non-builtin, like this:
>>
>>      ./net/shr.el:164:(define-obsolete-variable-alias 'shr-external-browser 'browse-url-secondary-browser-function "27.1")
>>
>>    Start with "emacs -Q", then execute with C-j in *scratch*:
>>
>>      (require 'browse-url)
>>      browse-url
>>
>>      browse-url-secondary-browser-function
>>      browse-url-default-browser
>>
>>      (require 'shr)
>>      shr
>>
>>      (unload-feature 'shr)
>>      nil
>>
>>      browse-url-secondary-browser-function
>>      => Lisp error: (void-variable browse-url-secondary-browser-function)
>>
>> My understanding is that `unload-feature' in
>>
>> case 1. tries to unbind BASE-VARIABLE of the alias, and not NEW-ALIAS,
>> and fails to do so and in
>>
>> case 2. unbinds both CURRENT-NAME and OBSOLETE-NAME.
>>
>> I would expect that in these cases `unload-feature' should unbind
>> NEW-ALIAS/OBSOLETE-NAME from the feature being unloaded, but leave
>> BASE-VARIABLE/CURRENT-NAME unchanged.  (Except of course if both items
>> of the alias originate from the same feature.)
> 
> Stefan, any suggestions?

Gentle ping to Stefan ...

... thanks!

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.