Re: [PATCH] diff-options.txt: correct command syntax

From: Martin Ågren <martin.agren@gmail.com>
Date: Feb 3, 2020, 06:24 UTC
Message-ID: <CAN0heSpDV2N2L4ukgdWxWJYJC1Hg9KYYkMC9MrqMGkuiv34AmQ@mail.gmail.com>
In-Reply-To: <20200202204739.GA24686@dinwoodie.org>

On Sun, 2 Feb 2020 at 21:47, Adam Dinwoodie <adam@dinwoodie.org> wrote:

Show 17 quoted lines

> On Sunday 02 February 2020 at 08:45 pm +0100, Martin Ågren wrote:
> > On Sun, 2 Feb 2020 at 20:24, Adam Dinwoodie <adam@dinwoodie.org> wrote:
>
> Ah, thank you!  I had completely misread what these examples were trying
> to achieve.  I think your example (or indeed anything from a different
> domain) would have avoided me getting confused in the first place.
> Although I'm much less fussed now I realise the problem here was
> entirely my understanding rather than an error in the docs.
>
> > BTW, I wonder what "in the same file" tries to say -- my hunch is we
> > could drop those words without any loss of correctness or readability.
> > Would you agree?
>
> I think "in the same file" is meaningful here: as I understand it both
> forms would find a commit that removed a line from one file and added it
> back to a _different_ file, but only the -G form would pick it when
> removed and added lines are in the same file.

You're right, it is needed. At least the way the example is given now, where there's some arbitrary amount of left-out context between the "+" and the "-" line, it's necessary to limit that by saying that it's in the same file. Because this is an example, we're allowed to make it as concrete as we see fit. For example:

 To illustrate the difference between `-S<regex> --pickaxe-regex` and
 `-G<regex>`, consider a commit with the following diff:
 +
 ----
 -    hit = !frotz(nitfol, mf2.ptr, 1, 0);
 +    return !frotz(nitfol, two->ptr, 1, 0);
 ----
 +
 While `git log -G"frotz\(nitfol"` will show this commit, `git log
 -S"frotz\(nitfol" --pickaxe-regex` will not (because the number of
 occurrences of that string did not change).

Or does that make it too specific, i.e., could this give readers the wrong impression that -G and/or -S and/or the difference explained here only apply to such "trivial" cases?

Martin