push-to-deploy: allow pushing into an unborn branch and updating it

Setting receive.denycurrentbranch to updateinstead and pushing into
the current branch, when the working tree and the index is truly
clean, is supposed to reset the working tree and the index to match
the tree of the pushed commit.  This did not work when pushing into
an unborn branch.

The code that drives push-to-checkout hook needs no change, as the
interface is defined so that hook can decide what to do when the
push is coming to an unborn branch and take an appropriate action
since the beginning.

Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 54 insertions, 1 deletions

diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index e4436c1..4f659d9 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -1430,8 +1430,22 @@ test_expect_success 'receive.denyCurrentBranch = updateInstead' '
 		test $(git -C .. rev-parse HEAD^^) = $(git rev-parse HEAD) &&
 		git diff --quiet &&
 		test fifth = "$(cat path3)"
-	)
+	) &&
 
+	# (5) push into void
+	rm -fr void &&
+	git init void &&
+	(
+		cd void &&
+		git config receive.denyCurrentBranch updateInstead
+	) &&
+	git push void master &&
+	(
+		cd void &&
+		test $(git -C .. rev-parse master) = $(git rev-parse HEAD) &&
+		git diff --quiet &&
+		git diff --cached --quiet
+	)
 '
 
 test_expect_success 'updateInstead with push-to-checkout hook' '
@@ -1494,6 +1508,45 @@ test_expect_success 'updateInstead with push-to-checkout hook' '
 		test "$(cat path5)" = irrelevant &&
 		test "$(git diff --name-only --cached HEAD)" = path5 &&
 		test $(git -C .. rev-parse HEAD) = $(git rev-parse HEAD)
+	) &&
+
+	# push into void
+	rm -fr void &&
+	git init void &&
+	(
+		cd void &&
+		git config receive.denyCurrentBranch updateInstead &&
+		write_script .git/hooks/push-to-checkout <<-\EOF
+		if git rev-parse --quiet --verify HEAD
+		then
+			has_head=yes
+			echo >&2 updating from $(git rev-parse HEAD)
+		else
+			has_head=no
+			echo >&2 pushing into void
+		fi
+		echo >&2 updating to "$1"
+
+		git update-index -q --refresh &&
+		case "$has_head" in
+		yes)
+			git read-tree -u -m HEAD "$1" ;;
+		no)
+			git read-tree -u -m "$1" ;;
+		esac || {
+			status=$?
+			echo >&2 read-tree failed
+			exit $status
+		}
+		EOF
+	) &&
+
+	git push void master &&
+	(
+		cd void &&
+		git diff --quiet &&
+		git diff --cached --quiet &&
+		test $(git -C .. rev-parse HEAD) = $(git rev-parse HEAD)
 	)
 '