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

[Junio C Hamano <gitster@pobox.com>]

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

> Hi Junio,
>
> On Wed, 15 May 2019, Junio C Hamano wrote:
>
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>>
>> I was imagining what would happen if we treat _everything_ in the two
>> directories being compared by "difftool --dir-diff --no-index" as if it
>> is tracked.
>
> Isn't this exactly what `git difftool --no-index` *without* `--dir-diff`
> does already (although without copying or hardlinking or symlinking any
> files)?

If that is the case, then I would imagine that running that command
for the user, instead of refusing to work, would give a more
pleasant end-user experience.  No?

Unless we anticipate that we might dwim incorrectly and mistake a
request to compare two things, to which the distinction between
tracked and untracked matters, as a request to compare two
directories that are not under Git control, that is.  If such an
incorrect dwim were a possibility, then it is helpful to refuse with
"when comparing two non-git-controlled directories, you cannot use
the '--dir-diff' mode", as that would not silently give an incorrect
output to the users.

In any case, all of the above can be left for future improvements.
Getting close to the final, I think it is preferrable to have a
"refuse to stop early" (i.e. the patch that is already in 'next')
instead of "do what the user meant" whose implementation may become
more involved (and error prone).

Thanks.