Re: [PATCH 2/2] built-in rebase: reinstate `checkout -q` behavior where appropriate

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Nov 12, 2018, 11:42 UTC
Message-ID: <nycvar.QRO.7.76.6.1811121235120.39@tvgsbejvaqbjf.bet>
In-Reply-To: <xmqq1s7r3pqy.fsf@gitster-ct.c.googlers.com>

Hi Junio,

On Mon, 12 Nov 2018, Junio C Hamano wrote:

Show 26 quoted lines

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> >> >  static int reset_head(struct object_id *oid, const char *action,
> >> > -		      const char *switch_to_branch, int detach_head,
> >> > +		      const char *switch_to_branch,
> >> > +		      int detach_head, int reset_hard,
> >> 
> >> It might be worth switching to a single flag variable here. It would
> >> make calls like this:
> >> 
> >> > -	if (reset_head(&options.onto->object.oid, "checkout", NULL, 1,
> >> > +	if (reset_head(&options.onto->object.oid, "checkout", NULL, 1, 0,
> >> >  	    NULL, msg.buf))
> >> 
> >> a little more self-documenting (if a little more verbose).
> >
> > I thought about that, but for just two flags? Well, let me try it and see
> > whether I like the result ;-)
> 
> My rule of thumb is that repeating three times is definitely when we
> should consolidate separate ones into a single flag word, and twice
> is a borderline.
> 
> For two-time repetition, it is often worth fixing when somebody
> notices it during the review, as that is a sign that repetition,
> even a minor one, disturbed a reader enough to point out.

That's my thought exactly, hence I looked into it. The end result is actually easier to read, in particular the commit that re-introduces the `reset --hard` behavior: it no longer touches *all* callsites of `reset_head()` but only the relevant ones.

> On the other hand, for a file-scope static that is likely to stay as a
> non-API function but a local helper, it may not be worth it.

Oh, do you think that `reset_head()` is likely to stay as non-API function? I found myself in the need of repeating this tedious unpack_trees() dance quite a few times over the past two years, and it is *always* daunting because the API is *that* unintuitive.

So I *do* hope that `reset_head()` will actually be moved to reset.[ch] eventually, and callsites e.g. in `sequencer.c` will be converted from calling `unpack_trees()` to calling `reset_head()` instead.

v2 on the way, Dscho

Show 21 quoted lines

> So I am OK either way, slightly in favor of fixing it while we
> remember.
> 
> 
> >> This one could actually turn into:
> >> 
> >>   ret = error(...);
> >>   goto leave_reset_head;
> >> 
> >> now. We don't have to worry about an uninitialized desc.buffer anymore
> >> (as I mentioned in the previous email), because "nr" would be 0.
> >> 
> >> It doesn't save any lines, though (but maybe having a single
> >> cleanup/exit point would make things easier to read; I dunno).
> >
> > But you're right, of course. Consistency makes for easier-to-read code.
> 
> Yup, that does sound good.
> 
> Thanks.
>