merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 136 insertions, 0 deletions

diff --git a/third_party/git/t/t1416-ref-transaction-hooks.sh b/third_party/git/t/t1416-ref-transaction-hooks.sh
new file mode 100755
index 0000000000..f6e741c6c0
--- /dev/null
+++ b/third_party/git/t/t1416-ref-transaction-hooks.sh
@@ -0,0 +1,136 @@
+#!/bin/sh
+
+test_description='reference transaction hooks'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	mkdir -p .git/hooks &&
+	test_commit PRE &&
+	PRE_OID=$(git rev-parse PRE) &&
+	test_commit POST &&
+	POST_OID=$(git rev-parse POST)
+'
+
+test_expect_success 'hook allows updating ref if successful' '
+	test_when_finished "rm .git/hooks/reference-transaction" &&
+	git reset --hard PRE &&
+	write_script .git/hooks/reference-transaction <<-\EOF &&
+		echo "$*" >>actual
+	EOF
+	cat >expect <<-EOF &&
+		prepared
+		committed
+	EOF
+	git update-ref HEAD POST &&
+	test_cmp expect actual
+'
+
+test_expect_success 'hook aborts updating ref in prepared state' '
+	test_when_finished "rm .git/hooks/reference-transaction" &&
+	git reset --hard PRE &&
+	write_script .git/hooks/reference-transaction <<-\EOF &&
+		if test "$1" = prepared
+		then
+			exit 1
+		fi
+	EOF
+	test_must_fail git update-ref HEAD POST 2>err &&
+	test_i18ngrep "ref updates aborted by hook" err
+'
+
+test_expect_success 'hook gets all queued updates in prepared state' '
+	test_when_finished "rm .git/hooks/reference-transaction actual" &&
+	git reset --hard PRE &&
+	write_script .git/hooks/reference-transaction <<-\EOF &&
+		if test "$1" = prepared
+		then
+			while read -r line
+			do
+				printf "%s\n" "$line"
+			done >actual
+		fi
+	EOF
+	cat >expect <<-EOF &&
+		$ZERO_OID $POST_OID HEAD
+		$ZERO_OID $POST_OID refs/heads/master
+	EOF
+	git update-ref HEAD POST <<-EOF &&
+		update HEAD $ZERO_OID $POST_OID
+		update refs/heads/master $ZERO_OID $POST_OID
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'hook gets all queued updates in committed state' '
+	test_when_finished "rm .git/hooks/reference-transaction actual" &&
+	git reset --hard PRE &&
+	write_script .git/hooks/reference-transaction <<-\EOF &&
+		if test "$1" = committed
+		then
+			while read -r line
+			do
+				printf "%s\n" "$line"
+			done >actual
+		fi
+	EOF
+	cat >expect <<-EOF &&
+		$ZERO_OID $POST_OID HEAD
+		$ZERO_OID $POST_OID refs/heads/master
+	EOF
+	git update-ref HEAD POST &&
+	test_cmp expect actual
+'
+
+test_expect_success 'hook gets all queued updates in aborted state' '
+	test_when_finished "rm .git/hooks/reference-transaction actual" &&
+	git reset --hard PRE &&
+	write_script .git/hooks/reference-transaction <<-\EOF &&
+		if test "$1" = aborted
+		then
+			while read -r line
+			do
+				printf "%s\n" "$line"
+			done >actual
+		fi
+	EOF
+	cat >expect <<-EOF &&
+		$ZERO_OID $POST_OID HEAD
+		$ZERO_OID $POST_OID refs/heads/master
+	EOF
+	git update-ref --stdin <<-EOF &&
+		start
+		update HEAD POST $ZERO_OID
+		update refs/heads/master POST $ZERO_OID
+		abort
+	EOF
+	test_cmp expect actual
+'
+
+test_expect_success 'interleaving hook calls succeed' '
+	test_when_finished "rm -r target-repo.git" &&
+
+	git init --bare target-repo.git &&
+
+	write_script target-repo.git/hooks/reference-transaction <<-\EOF &&
+		echo $0 "$@" >>actual
+	EOF
+
+	write_script target-repo.git/hooks/update <<-\EOF &&
+		echo $0 "$@" >>actual
+	EOF
+
+	cat >expect <<-EOF &&
+		hooks/update refs/tags/PRE $ZERO_OID $PRE_OID
+		hooks/reference-transaction prepared
+		hooks/reference-transaction committed
+		hooks/update refs/tags/POST $ZERO_OID $POST_OID
+		hooks/reference-transaction prepared
+		hooks/reference-transaction committed
+	EOF
+
+	git push ./target-repo.git PRE POST &&
+	test_cmp expect target-repo.git/actual
+'
+
+test_done