Subject: Re: [PATCH] unpack-trees.c: fix writing "link" index ext with null base oid

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Tue, 12 Feb 2019 10:36:01 +0100

On Sat, Feb 09 2019, Nguyễn Thái Ngọc Duy wrote:

I ran into this bug in the past but wasn't able to reproduce it long
enough to track it down. Thanks for the fix.

It would be nice to have a test for it if it's easily narrowed down,
tricky edge cases we fix are worth testing for...

>  I considered adding a test, but since the problem is a warning, not
>  sure how to catch that. And a test would not be able to verify all
>  changes in this patch anyway.

You'd write the test like this:

    git [...] 2>stderr &&
    test_i18ngrep "could not.*000000000" stderr

Or something like that. We have a lot of tests like this already, some
can be found with:

    git grep -B1 test_i18ngrep.*stderr

So something being a warning shouldn't stop us from testing for it.