Re: [PATCH] Documentation/merge-options: clarify --squash behavior

[Vishal Verma <vishal@stellar.sh>]

On Thu, 2019-04-25 at 13:16 +0900, Junio C Hamano wrote:
> 
> I think it is bad to silently ignore the option.  With or without
> this documentation update, I think it is sensible to update the code
> so that it errors out when "--squash --commit" are both given at the
> same time, just like when "--squash --no-ff" is given.

Yes that makes sense.

> Or make it "just work" as you said.  Using a boolean variable as
> tristate is something we do in many places and it by itself is not a
> rocket science.  You initialize the variable to -1 (unset), let
> parse_options() to set it to 0/1 when "--[no-]commit" is seen, and
> inspect after parse_options() finishes.  If the variable is still
> -1, you know the user wants "the default" behaviour.

Ah I see - I was conflating OPT_BOOL with the parameter being a boolean
as well without checking, but I see now that isn't the case.

> 
> The "default" behaviour you are proposing would probably be
> something like
> 
>         if (option_commit < 0) {
>                 /* 
>                  * default to record the result in a commit.
>                  * but --squash traditionally does not.
>                  */
>                 if (!squash)
>                         option_commit = 1;
>                 else
>                         option_commit = 0;
>         }
> 
> But I suspect that the option parsing part is the least difficult in
> the "make it just work" change.  That is because I think that the
> machinery to record the result in a commit is not expecting to be
> asked to create a single-parent commit to record the result of the
> squashing, so there may be need for adjusting to how the result
> wants to be recorded before the code makes a commit.

Yes I was going to try to allow the commit option as an experiment, and
just see what happens. For now I'll send a v2 that has a doc update as
well as prints a warning using the above technique.

I'll dig more into what allowing --commit actually means (as time
allows) - I'm definitely a newbie with git internals, and indeed this is
my first posting here.

Thanks for the feedback!

	-Vishal