script with rev-list instead of log

Because log.decorate now shows decorations for --pretty=oneline,
we must explicitly turn it off when scripting. Otherwise,
users with log.decorate set will get cruft like:

  $ git stash
  Saved working directory and index state WIP on master:
    2c1f7f5 (HEAD, master) commit subject

Instead of adding --no-decorate to the log command line,
let's just use the rev-list plumbing interface instead,
which does the right thing.

git-submodule has a similar call. Since it just counts the
commit lines, nothing is broken, but let's switch it, too,
for the sake of consistency and cleanliness.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/git-stash.sh b/git-stash.sh
index 3a0685f..0726a4a 100755
--- a/git-stash.sh
+++ b/git-stash.sh
@@ -57,7 +57,7 @@
 	# state of the base commit
 	if b_commit=$(git rev-parse --verify HEAD)
 	then
-		head=$(git log --no-color --abbrev-commit --pretty=oneline -n 1 HEAD --)
+		head=$(git rev-list --oneline -n 1 HEAD --)
 	else
 		die "You do not have the initial commit yet"
 	fi