Re: [PATCH 2/2] sequencer.c: plug mem leak in git_sequencer_config

[Jeff King <peff@peff.net>]

On Thu, Jun 21, 2018 at 09:03:05AM +0200, Johannes Schindelin wrote:

> > > And at that point, maybe
> > > 
> > > 	char *some_var = xstrdup("default");
> > > 	git_config_string(&some_var, ...);
> > > 
> > > that takes "char **" and frees the current storage before assigning to
> > > it may be simpler than the two-variable approach.
> > 
> > That _is_ much nicer, but you cannot use xstrdup() as the initializer
> > for a global "static char *some_var", which is what the majority of the
> > config variables are. It's this "static initializer sometimes, run-time
> > heap sometimes" duality to the variables that makes handling it such a
> > pain.
> 
> This makes me think of Michael's proposal to teach strbuf some sort of
> STRBUF_INIT_CONST("default") which would set the appropriate len and set
> alloc to 0.
> 
> That way, we could turn those settings into strbufs that only allocate
> memory when/if needed.

Yes! I should have thought about that as soon as I started saying "you
need two variables...". That is a good indication that you need a
struct. ;)

I think the result would be quite readable and pleasant to work with.

I tried to dig up previous conversations about this to see if there were
any patches shown, but I couldn't find any (mostly I found the
conversation about using stack buffers in strbufs, which is not quite
the same thing, since we _do_ want to write in those).

-Peff