Re: [PATCH] setup: only die on invalid .git under RUN_SETUP

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

On Thu, Jul 22 2021, Junio C Hamano wrote:

> Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:
>
>> Change RUN_SETUP_GENTLY to stop dying if e.g. the .git is "not a
>> repo". This means that we now recover in cases like:
>>
>>     $ echo "gitdir: /foo/bar" > .git
>>     $ git ls-remote https://github.com/torvalds/linux
>>     [... ls-remote output ...]
>>
>> But not (as intended):
>>
>>     $ git rev-parse HEAD
>>     fatal: not a git repository: /foo/bar
>
> I am of two minds.  ls-remote is benign in that it behaves more or
> less identically when given certain types of args, and the above may
> be a strict improvement (but it does fail if you did not use URL but
> use a remote nickname you thought you configured in the repository
> in such a situation).  There however are a few niche commands that
> work inside and outside a repository and they work differently.  For
> example, if you do
>
>   $ git diff file1 file2
>
> in such a corrupt repository, I'd prefer to see the command _fail_
> to nudge the user to look into the situation, instead of taking the
> output (which degenerates to "git diff --no-index file1 file2"
> outside a repository) blindly as a patch that shows the changes
> relative to the index for these two paths.

Yes it comes down to what we think RUN_SETUP_GENTLY and
setup_git_directory_gently() should be doing.

I.e. is &nongit_ok supposed to be a binary "repo you can use"/"[...]
can't use", or a tri-state of that plus "this looks like it's supposed
to be a repo, but it's broken, so let's die".

Anyway, if you're not happy with this pretty much as-is consider it
dropped from my side, because I think the next step would be to do some
more work on e.g. split up RUN_SETUP_GENTLY into a mode that makes sense
for "diff", and another for "bugreport" and "ls-remote". I figured this
was an easy bugfix, but if not perhaps Tom Cooks wants to pick this
up...

I guess another easy alternative would be to issue a warning() in this
case, which is a relatively light refactoring of passing an error
message up from the relevant function(s) instead of having it die()
directly.