Re: js/difftool-no-index, was Re: What's cooking in git.git (May 2019, #02; Tue, 14)

From: Junio C Hamano <gitster@pobox.com>
Date: May 15, 2019, 01:28 UTC
Message-ID: <xmqqef508q0y.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <nycvar.QRO.7.76.6.1905141153150.44@tvgsbejvaqbjf.bet>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

Show 17 quoted lines

> Hi Junio,
>
> On Tue, 14 May 2019, Junio C Hamano wrote:
>
>> * js/difftool-no-index (2019-05-09) 1 commit
>>  - difftool --no-index: error out on --dir-diff (and don't crash)
>>
>>  The "--dir-diff" mode of "git difftool" is not useful in "--no-index"
>>  mode; they are now explicitly marked as mutually incompatible.
>>
>>  Will merge to 'next'.
>
> Seeing as the following is a part of v2.22.0-rc0's release notes:
>
> 	 * "git difftool" can now run outside a repository.
>
> maybe we could get this to `master` instead of `next`?

There is no 'instead of'.  Topics advance one step at a time.

I do not recall seeing you respond to my review comments on the "error out" patch <xmqqv9ykdr1w.fsf@gitster-ct.c.googlers.com>, but thinking about it further, assuming that my rephrasing of your justification in my review was correct, I wonder if it is even more correct if we do not error out but simply behave as if "--dir-diff" option were not given.

That is, if there were some way to distinguish tracked and untracked paths in --no-index mode, --dir-diff would copy only the tracked parts to temporary directories and run tree comparison. Since there is no "untracked paths" by definition in --no-index mode, we do not even have to make copies but just compare the two directories given using the same tree comparison tool.

Wouldn't that be more useful behaviour than telling the end users to run the backend tree comparison tool themselves?