Re: [PATCH] Fix PR gdb/16999

[Pedro Alves <palves@redhat.com>]

On 05/13/2015 11:38 PM, Patrick Palka wrote:
> On Wed, May 13, 2015 at 6:24 PM, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:
>>>
>>> When GDB reads a nonsensical value for the HISTSIZE environment variable
>>> variable, i.e. one that is non-numeric or negative, GDB then sets its
>>> history size to 0.  This behavior is contrary to that of bash, which
>>> defaults the history size to unlimited in such cases.
>>>
>>> This patch makes the behavior of invalid HISTSIZE match that of bash.
>>> When we encounter an invalid HISTSIZE we now set the history size to
>>> unlimited instead of 0.

...

> I personally don't like GDB's behavior because 1) it's not consistent
> with bash and 2) it's unforgiving: a mere typo when setting HISTSIZE
> will truncate the entire history file at exit.

I agree.  Users can well set HISTSIZE to -1 in their ~/.bashrc to affect
bash's history, and then it's very annoying that GDB ends up with no
history... As we're reusing this environment variable from bash, I
think the right thing to do is follow whatever bash does.

(BTW, like we have GDBHISTFILE vs bash's HISTFILE, it may be
good to have a GDBHISTSIZE to override HISTSIZE without affecting
bash.)

Thanks,
Pedro Alves