Re: [PATCH v3 2/2] commit-graph.c: no lazy fetch in lookup_commit_in_graph()

> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>
>> On Thu, Jun 30 2022, Johannes Schindelin wrote:
>>
>>> Hi Junio,
>>>
>>> On Tue, 28 Jun 2022, Junio C Hamano wrote:
>>>
>>>> Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:
>>>>
>>>> >> +test_expect_success 'setup: prepare a repository with commit-graph contains the commit' '
>>>> >> +	git init with-commit-graph &&
>>>> >> +	echo "$(pwd)/with-commit/.git/objects" \
>>>> >> +		>with-commit-graph/.git/objects/info/alternates &&
>>>> >
>>>> > nit: you can use $PWD instead of $(pwd).
>>>>
>>>> We can, and it would not make any difference on non-Windows.
>>>>
>>>> But which one should we use to cater to Windows?  $(pwd) is a full
>>>> path in Windows notation "C:\Program Files\Git\..." while $PWD is
>>>> MSYS style "/C/Program Files/Git/..." or something like that, IIRC?
>>>
>>> Indeed, and since the `alternates` file is supposed to be read by
>>> `git.exe`, a non-MSYS program, the original was good, and the nit
>>> suggested the incorrect form.
>>
>> I looked at t5615-alternate-env.sh which does the equivalent of:
>>
>> 	GIT_ALTERNATE_OBJECT_DIRECTORIES="$PWD/one.git/objects:$PWD/two.git/objects" \
>>         	git cat-file [...]
>>
>> We run that test on all our platforms, does the $PWD form work in the
>> environment variable, but not when we write it to the "alternates" file?
>> Or is there some other subtlety there that I'm missing?
>
> I am also curious to see a clear and concise explanation so that we
> do not have to repeat this discussion later.  We have
>
>  - When a test checks for an absolute path that a git command generated,
>    construct the expected value using $(pwd) rather than $PWD,
>    $TEST_DIRECTORY, or $TRASH_DIRECTORY. It makes a difference on
>    Windows, where the shell (MSYS bash) mangles absolute path names.
>    For details, see the commit message of 4114156ae9.
>
> in t/README, but even with the log mesasge of 4114156a (Tests on
> Windows: $(pwd) must return Windows-style paths, 2009-03-13) [*1*],
> I have no idea what makes the thing you found in t5615 work and your
> suggestion to use $PWD in the new one not work.
>
> GIT_ALTERNATE_OBJECT_DIRECTORIES is a PATH_SEP (not necessarily a
> colon) separated list, and I think the way t5615 uses it is broken
> on Windows where PATH_SEP is defined as semicolon without the $PWD
> vs $(pwd) issue.  Is the test checking the right thing?