[RFC/PATCH] Re: git submodule -b ... of current HEAD fails

[Jonathan Nieder <jrnieder@gmail.com>]

	git submodule add -b $branch $repository

fails when HEAD already points to $branch in $repository.

Reported-by: Klaus Ethgen <Klaus@Ethgen.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
Hi Klaus,

Klaus Ethgen wrote at <http://bugs.debian.org/605600>:

> Strange problem, if I create a submodule of an other repository giving
> the currently used HEAD branch I get the error: »fatal: git checkout:
> branch myimbabranch already exists« while when giving other branch
> work well.

Interesting.  The problem is in cmd_add of git-submodule.sh; this
patch demonstrates a quick fix.  Jens, any idea why git submodule
is not using "clone --branch" directly?

diff --git a/git-submodule.sh b/git-submodule.sh
index 33bc41f..6242d7f 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -241,7 +241,7 @@ cmd_add()
 			# ash fails to wordsplit ${branch:+-b "$branch"...}
 			case "$branch" in
 			'') git checkout -f -q ;;
-			?*) git checkout -f -q -b "$branch" "origin/$branch" ;;
+			?*) git checkout -f -q -B "$branch" "origin/$branch" ;;
 			esac
 		) || die "Unable to checkout submodule '$path'"
 	fi