[PATCH] merge: allow merging into a yet-to-be-born branch.

[Junio C Hamano <junkio@cox.net>]

Signed-off-by: Junio C Hamano <junkio@cox.net>
---

 * This is not useful in a freshly initialized repository, since
   it would not have any commits that you can use with the
   command.  But you can push into the repository and then later
   use the updated branch to merge into your 'master' branch
   that still does not exist yet.

 git-merge.sh |   18 ++++++++++++++++++
 1 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/git-merge.sh b/git-merge.sh
index 25deb1e..dd4e83d 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -159,6 +159,24 @@ then
 	shift
 	head_arg="$1"
 	shift
+elif ! git-rev-parse --verify HEAD 2>/dev/null
+then
+	# If the merged head is a valid one there is no reason to
+	# forbid "git merge" into a branch yet to be born.  We do
+	# the same for "git pull".
+	if test 1 -ne $#
+	then
+		echo >&2 "Can merge only exactly one commit into empty head"
+		exit 1
+	fi
+
+	rh=$(git rev-parse --verify "$1^0") ||
+		die "$1 - not something we can merge"
+
+	git-update-ref -m "initial pull" HEAD "$rh" "" &&
+	git-read-tree --reset -u HEAD
+	exit
+
 else
 	# We are invoked directly as the first-class UI.
 	head_arg=HEAD
-- 
1.4.4.g26805