Subject: Re: bug#6035: M-x gdb crashes

From: Arni Magnusson <[email-masked]>
Date: Tue, 6 Jul 2010 08:47:20 +0000 (GMT)

C-c C-char: reserved for major and minor modes (source: elisp manual)

C-x C-char: free game for anyone, potential tug-of-wars between users and 
modes, but no should pose no danger of crashing a mode (source: my 
interpretation and experience)

Given the nature of Emacs, some tug-of-war of keybindings can be expected. 
Many of my mode hooks, for example, rebind M-n and M-p to what I like them 
to do, overriding what the mode author thought I might like. This is 
harmless, and has not crashed any mode. The elisp manual (23.2.2) allows 
major modes to use these and other keystrokes, but I'm sure many Emacs 
users have bound them to generic functions they find useful in all modes.

We sound like lawyers here, but all I'm asking is whether it's easy to 
prevent M-x gdb from crashing if C-x C-a is bound. If it's not easy, then 
so be it; the current error message accurately describes the quirk.

Cheers,

Arni

On Tue, 6 Jul 2010, Lennart Borgman wrote:

> On Tue, Jul 6, 2010 at 2:27 AM, Arni Magnusson <[email-masked]> wrote:
>>
>> I can find no warning
>> against redefining C-x C-char, such as C-x C-a.
>
> The elisp manual chapter mentioned before here
>
>   (info "(elisp) Key Binding Conventions")
>
> says that
>
>   * Sequences consisting of `C-c' followed by a control character or a
>     digit are reserved for major modes.
>
> So it looks to me like GUD does follow that rule.
>
> Maybe the error message could include a link to that part of the elisp
> manual, but that would rather be a general thing in Emacs, not
> specific to GUD.
>