From 8f22e3b529f02ad4b7b91fe40903f84ce4f11612 Mon Sep 17 00:00:00 2001
From: Stephen Haberman <stephen@exigencecorp.com>
Date: Mon, 29 Sep 2008 03:36:54 -0500
Subject: [PATCH] Append to a separate "commitnumbers" to avoid race
 conditions.

Also use `git tag` to create the tag instead of mucking directly with
packed-refs. The refs will end up there eventually upon gc.
---
 server/post-receive-assign-commit-numbers          | 13 +++++--------
 ...00-server-post-receive-assign-commit-numbers.sh | 14 +++++++-------
 2 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/server/post-receive-assign-commit-numbers b/server/post-receive-assign-commit-numbers
index 9d424b1..6ed313d 100644
--- a/server/post-receive-assign-commit-numbers
+++ b/server/post-receive-assign-commit-numbers
@@ -5,15 +5,12 @@
 while read oldrev newrev refname ; do
 	set_new_commits
 	echo "$new_commits" | git rev-list --reverse --stdin | while read commit ; do
-		cat $GIT_DIR/packed-refs | grep --quiet "$commit"
+		touch "$GIT_DIR/commitnumbers"
+		cat "$GIT_DIR/commitnumbers" | grep --quiet "$commit"
 		if [ $? -ne 0 ] ; then
-			current=$(cat $GIT_DIR/packed-refs | grep "refs/tags/r/" | tail -n 1 | grep -oP "r\/\d+" | grep -oP "\d+")
-			if [ $? -ne 0 ] ; then
-				next="0"
-			else
-				next=$(($current + 1))
-			fi
-			echo "$commit refs/tags/r/$next" >> $GIT_DIR/packed-refs
+			echo "$commit" >> "$GIT_DIR/commitnumbers"
+			number=$(cat "$GIT_DIR/commitnumbers" | grep --line-number "$commit" | grep -oP "^\d+(?=:)")
+			git tag "r/$number" "$commit"
 		fi
 	done
 done
diff --git a/tests/t3200-server-post-receive-assign-commit-numbers.sh b/tests/t3200-server-post-receive-assign-commit-numbers.sh
index 6e76cd6..4f8f924 100644
--- a/tests/t3200-server-post-receive-assign-commit-numbers.sh
+++ b/tests/t3200-server-post-receive-assign-commit-numbers.sh
@@ -25,8 +25,8 @@ test_expect_success 'assign one new commit' '
 	git push origin master &&
 	git fetch &&
 
-	test "$(git rev-parse HEAD)" = "$(git rev-parse r/0)"
-	test "$(git describe --tags)" = "r/0"
+	test "$(git rev-parse HEAD)" = "$(git rev-parse r/1)"
+	test "$(git describe --tags)" = "r/1"
 '
 
 test_expect_success 'assign two new commits' '
@@ -37,11 +37,11 @@ test_expect_success 'assign two new commits' '
 	git push origin master &&
 	git fetch &&
 
-	test "$(git rev-parse HEAD)" = "$(git rev-parse r/2)"
-	test "$(git describe --tags)" = "r/2"
+	test "$(git rev-parse HEAD)" = "$(git rev-parse r/3)"
+	test "$(git describe --tags)" = "r/3"
 
-	test "$(git rev-parse HEAD^)" = "$(git rev-parse r/1)"
-	test "$(git describe --tags HEAD^)" = "r/1"
+	test "$(git rev-parse HEAD^)" = "$(git rev-parse r/2)"
+	test "$(git describe --tags HEAD^)" = "r/2"
 '
 
 test_expect_success 'pushing commits to a new branch does not reassign' '
@@ -50,7 +50,7 @@ test_expect_success 'pushing commits to a new branch does not reassign' '
 	git push origin topica &&
 	git fetch &&
 
-	! git rev-parse r/3
+	! git rev-parse r/4
 '
 
 test_done
-- 
2.20.1