From db912f569002e00ab208346e9d5a5fe311e7b591 Mon Sep 17 00:00:00 2001
From: Stephen Haberman <stephen@exigencecorp.com>
Date: Sun, 24 Aug 2008 16:31:11 -0500
Subject: [PATCH] Upgrade update-stable to enforce candidate/topic as well.

For now we're still doing the topic is locked upon candidate
creation. I'd still prefer remerging.
---
 server/update-stable                          | 137 ++++++++++++------
 tests/t2102-server-update-stable-candidate.sh |  89 ++++++++++++
 2 files changed, 180 insertions(+), 46 deletions(-)
 create mode 100644 tests/t2102-server-update-stable-candidate.sh

diff --git a/server/update-stable b/server/update-stable
index 6c89e51..fb1a8e6 100644
--- a/server/update-stable
+++ b/server/update-stable
@@ -1,10 +1,18 @@
 #!/bin/sh
 
 #
-# This enforces stable only moving in the approved way, which
-# is via empty (no change) merge commits. The rationale is that
-# in the DAG we want a simple, one-commit move from each release
-# to the next.
+# This enforces stable/candidate/topic patterns.
+#
+# Specifically:
+#
+# * stable must be moved 1 merge commit at a time (see below)
+# * candidates/topics are frozen once merged into stable
+# * topics are frozen once merged into candidates
+#
+# For DAG aesthetics, we prefer stable only moving in the approved way,
+# which is via empty (no change) merge commits. The rationale is that
+# in the DAG we want a simple, one-commit move from each release to the
+# next.
 #
 # We started out with:
 #
@@ -40,56 +48,93 @@ refname="$1"
 oldrev="$2"
 newrev="$3"
 
-if expr "$oldrev" : '0*$' >/dev/null ; then
+. $(dirname $0)/functions
+set_change_type
+
+if [[ "$refname" =~ refs/heads/(.*) ]] ; then
+	short_refname=${refname##refs/heads/}
+else
 	exit 0
 fi
 
-if [ "$refname" != "refs/heads/stable" ] ; then
+# create/delete is okay
+if [ "$change_type" != "update" ] ; then
 	exit 0
 fi
 
-# read backwards:
-# - all commits from old..new
-# - unless they were already pointed to by a branch
-# = all new commits on stable
-count=$(git rev-parse --not --branches | git rev-list --stdin $oldrev..$newrev | wc -l)
-if [ "$count" -ne "1" ] ; then
-	echo "----------------------------------------------------"
-	echo
-	echo "Moving stable must entail a single commit"
-	echo
-	echo "----------------------------------------------------"
-	exit 1
-fi
+if [ "$short_refname" == "stable" ] ; then
+	# Stable enforcement
 
-number_of_parents=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | wc -l)
-if [ "$number_of_parents" -ne "2" ] ; then
-	echo "----------------------------------------------------"
-	echo
-	echo "Moving stable must entail a merge commit"
-	echo
-	echo "----------------------------------------------------"
-	exit 1
-fi
+	# read backwards:
+	# - all commits from old..new
+	# - unless they were already pointed to by a branch
+	# = all new commits on stable
+	count=$(git rev-parse --not --branches | git rev-list --stdin $oldrev..$newrev | wc -l)
+	if [ "$count" -ne "1" ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "Moving stable must entail a single commit"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
 
-first_parent=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | head --lines=1)
-if [ "$first_parent" != "$oldrev" ] ; then
-	echo "----------------------------------------------------"
-	echo
-	echo "Moving stable must have the previous stable as the first parent"
-	echo
-	echo "----------------------------------------------------"
-	exit 1
-fi
+	number_of_parents=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | wc -l)
+	if [ "$number_of_parents" -ne "2" ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "Moving stable must entail a merge commit"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
+
+	first_parent=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | head --lines=1)
+	if [ "$first_parent" != "$oldrev" ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "Moving stable must have the previous stable as the first parent"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
+
+	second_parent=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | tail --lines=1)
+	changed_lines=$(git diff $second_parent..$newrev | wc -l)
+	if [ "$changed_lines" -ne "0" ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "Moving stable must not result in any changes from $second_parent"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
+else
+	# Check if candidate/topic is already in stable
+	git branch --contains "$oldrev" | grep stable >/dev/null
+	if [ $? -eq 0 ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "$short_refname has been merged into stable"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
+
+	# For now candidates can mix amongst each other so early exit
+	if [[ "$refname" =~ refs/heads/candidate(.*) ]] ; then
+		exit 0
+	fi
 
-second_parent=$(git rev-list --no-walk --parents $newrev | sed 's/ /\n/g' | grep -v $newrev | tail --lines=1)
-changed_lines=$(git diff $second_parent..$newrev | wc -l)
-if [ "$changed_lines" -ne "0" ] ; then
-	echo "----------------------------------------------------"
-	echo
-	echo "Moving stable must not result in any changes from $second_parent"
-	echo
-	echo "----------------------------------------------------"
-	exit 1
+	# Check if topic is already in candidates
+	candidate=$(git branch --contains "$oldrev" | grep -oP candidate.* --max-count=1)
+	if [ $? -eq 0 ] ; then
+		echo "----------------------------------------------------"
+		echo
+		echo "$short_refname has been merged into $candidate"
+		echo
+		echo "----------------------------------------------------"
+		exit 1
+	fi
 fi
 
diff --git a/tests/t2102-server-update-stable-candidate.sh b/tests/t2102-server-update-stable-candidate.sh
new file mode 100644
index 0000000..45f1782
--- /dev/null
+++ b/tests/t2102-server-update-stable-candidate.sh
@@ -0,0 +1,89 @@
+#!/bin/sh
+
+test_description='server update candidate enforcer'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo setup >a &&
+	git add a &&
+	git commit -m "a" &&
+	git clone ./. server &&
+	git remote add origin ./server &&
+	rm -fr server/.git/hooks
+'
+
+# setup the update hook
+install_update_hook 'update-stable'
+
+test_expect_success 'initial stable commit works' '
+	# do one stable-less commit
+	echo $test_name >a &&
+	git commit -a -m "$test_name" &&
+	git push origin master &&
+
+	git checkout -b stable &&
+	git push origin stable &&
+	git config --add branch.stable.remote origin &&
+	git config --add branch.stable.merge refs/heads/stable
+'
+
+test_expect_success 'create topic1 and topic2' '
+	git checkout -b topic1 stable &&
+	echo "$test_name topic1" >a.topic1 &&
+	git add a.topic1 &&
+	git commit -m "start topic1" &&
+
+	git checkout -b topic2 stable &&
+	echo "$test_name topic2" >a.topic2 &&
+	git add a.topic2 &&
+	git commit -m "start topic2" &&
+
+	git push origin topic2 topic1
+'
+
+test_expect_success 'create candidate1' '
+	git checkout -b candidate1 stable &&
+	git merge topic1 topic2 &&
+	git push origin candidate1
+'
+
+test_expect_success 'topic1 cannot be changed' '
+	git checkout topic1 &&
+	echo "$test_name" >a.topic1 &&
+	git commit -a -m "$test_name" &&
+	! git push origin topic1 2>push.err &&
+	cat push.err | grep "topic1 has been merged into candidate1"
+'
+
+test_expect_success 'candidate1 can be changed' '
+	git checkout candidate1 &&
+	echo "$test_name" >a.topic1 &&
+	git commit -a -m "$test_name" &&
+	git push origin candidate1
+'
+
+test_expect_success 'merge candidate into stable' '
+	git checkout stable &&
+	git merge candidate1 --no-ff &&
+	git push origin stable
+'
+
+test_expect_success 'candidate cannot be changed' '
+	git checkout candidate1 &&
+	echo "$test_name" >a.topic1 &&
+	git commit -a -m "$test_name" &&
+	! git push origin candidate1 2>push.err &&
+	cat push.err | grep "candidate1 has been merged into stable"
+	! cat push.err | grep "candidate1 has been merged into candidate1"
+'
+
+test_expect_success 'topic1 cannot be changed' '
+	# It is already changed but error message should chagne
+	git checkout topic1 &&
+	! git push origin topic1 2>push.err &&
+	cat push.err | grep "topic1 has been merged into stable"
+'
+
+test_done
+
-- 
2.20.1