Re: [PATCH next] t7407: use 'cut' utility rather than bash's substring expansion notation

[Johan Herland <johan@herland.net>]

On Thursday 20 August 2009, Junio C Hamano wrote:
> Johan Herland <johan@herland.net> writes:
> >> - $sub1sha1 sub1 (${sub1sha1:0:7})
> >> - $sub2sha1 sub2 (${sub1sha1:0:7})
> >> + $sub1sha1 sub1 ($(echo $sub1sha1 | cut -c 1-7))
> >> + $sub2sha1 sub2 ($(echo $sub1sha1 | cut -c 1-7))
> >
> > Typo (both in the original, and the patch), should be:
> > 	$sub2sha1 sub2 ($(echo $sub2sha1 | cut -c 1-7))
> >
> >>   $sub3sha1 sub3 (heads/master)
> >>  EOF
> >
> > Otherwise:
> >
> > Acked-by: Johan Herland <johan@herland.net>
>
> Hmm, what does the command use to shorten these object names?  It may be
> safer and more correct to use "rev-parse --short" in case these object
> names were ambigous in their first 7 hexdigits.

git submodule status (which is what we're testing here) uses
'git describe' to generate the short object name (see
set_name_rev in git-submodule.sh). In this case, it falls back
to 'git describe --all --always', which calls find_unique_abbrev()
on the SHA1. 'git rev-parse --short' ends up calling the same
find_unique_abbrev(), so I guess it is better to use it here.

Try this instead:

From: Johan Herland <johan@herland.net>

Subject: [PATCH] t7407: Use 'rev-parse --short' rather than bash's substring expansion notation

The substring expansion notation is a bashism that we have not so far
adopted.  Use 'git rev-parse --short' instead, as this also handles
the case where the unique abbreviation is longer than 7 characters.

Suggested-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Johan Herland <johan@herland.net>
---
 t/t7407-submodule-foreach.sh |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/t/t7407-submodule-foreach.sh b/t/t7407-submodule-foreach.sh
index 25ec281..2a52775 100755
--- a/t/t7407-submodule-foreach.sh
+++ b/t/t7407-submodule-foreach.sh
@@ -201,14 +201,16 @@ submodulesha1=$(cd clone3/nested1/nested2/nested3/submodule && git rev-parse HEA
 sub1sha1=$(cd clone3/sub1 && git rev-parse HEAD)
 sub2sha1=$(cd clone3/sub2 && git rev-parse HEAD)
 sub3sha1=$(cd clone3/sub3 && git rev-parse HEAD)
+sub1sha1_short=$(cd clone3/sub1 && git rev-parse --short HEAD)
+sub2sha1_short=$(cd clone3/sub2 && git rev-parse --short HEAD)
 
 cat > expect <<EOF
  $nested1sha1 nested1 (heads/master)
  $nested2sha1 nested1/nested2 (heads/master)
  $nested3sha1 nested1/nested2/nested3 (heads/master)
  $submodulesha1 nested1/nested2/nested3/submodule (heads/master)
- $sub1sha1 sub1 (${sub1sha1:0:7})
- $sub2sha1 sub2 (${sub1sha1:0:7})
+ $sub1sha1 sub1 ($sub1sha1_short)
+ $sub2sha1 sub2 ($sub2sha1_short)
  $sub3sha1 sub3 (heads/master)
 EOF
 
-- 
1.6.4.304.g1365c.dirty

-- 
Johan Herland, <johan@herland.net>
www.herland.net