From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 28 Jan 2021 05:25:42 GMT
Subject: Re: [PATCH 02/27] sparse-index: implement ensure_full_index()
Message-ID: <xmqqmtwty6nd.fsf@gitster.c.googlers.com>
In-Reply-To: <CABPp-BE3tLmfwyncbdTKZUgLYH_8M9zMjH=+LJG4bdGcbYDPMg@mail.gmail.com>

Elijah Newren <newren@gmail.com> writes:

>>  1. ce->ce_mode == 01000755
>
> This is a weird number.  What's the reason for choosing it?  It looks
> deceptively close to 0100755, normal executable files, but has the
> extra 0, meaning that ce->ce_mode & S_IFMT is 0, suggesting it has no
> file type.
>
> Since it's a directory, why not use S_IFDIR (040000)?
>
> (GITLINK does use the weird 0160000 value, but it happens to be
> S_IFLNK | S_IFDIR == 0120000 | 040000, which conveys "it's both a
> directory and a symlink")

Yes, that combination of IFLNK/IFDIR was the reason why we use the
value.  I tend to think IFDIR is the best thing to use here.