push: Add support for pre-push hooks

Add support for a pre-push hook which can be used to determine if the
set of refs to be pushed is suitable for the target repository.  The
hook is run with two arguments specifying the name and location of the
destination repository.

Information about what is to be pushed is provided by sending lines of
the following form to the hook's standard input:

  <local ref> SP <local sha1> SP <remote ref> SP <remote sha1> LF

If the hook exits with a non-zero status, the push will be aborted.

This will allow the script to determine if the push is acceptable based
on the target repository and branch(es), the commits which are to be
pushed, and even the source branches in some cases.

Signed-off-by: Aaron Schrab <aaron@schrab.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 131 insertions, 0 deletions

diff --git a/t/t5571-pre-push-hook.sh b/t/t5571-pre-push-hook.sh
new file mode 100755
index 0000000000..6f9916a390
--- /dev/null
+++ b/t/t5571-pre-push-hook.sh
@@ -0,0 +1,131 @@
+#!/bin/sh
+
+test_description='check pre-push hooks'
+. ./test-lib.sh
+
+# Setup hook that always succeeds
+HOOKDIR="$(git rev-parse --git-dir)/hooks"
+HOOK="$HOOKDIR/pre-push"
+mkdir -p "$HOOKDIR"
+write_script "$HOOK" <<EOF
+cat >/dev/null
+exit 0
+EOF
+
+test_expect_success 'setup' '
+	git config push.default upstream &&
+	git init --bare repo1 &&
+	git remote add parent1 repo1 &&
+	test_commit one &&
+	git push parent1 HEAD:foreign
+'
+write_script "$HOOK" <<EOF
+cat >/dev/null
+exit 1
+EOF
+
+COMMIT1="$(git rev-parse HEAD)"
+export COMMIT1
+
+test_expect_success 'push with failing hook' '
+	test_commit two &&
+	test_must_fail git push parent1 HEAD
+'
+
+test_expect_success '--no-verify bypasses hook' '
+	git push --no-verify parent1 HEAD
+'
+
+COMMIT2="$(git rev-parse HEAD)"
+export COMMIT2
+
+write_script "$HOOK" <<'EOF'
+echo "$1" >actual
+echo "$2" >>actual
+cat >>actual
+EOF
+
+cat >expected <<EOF
+parent1
+repo1
+refs/heads/master $COMMIT2 refs/heads/foreign $COMMIT1
+EOF
+
+test_expect_success 'push with hook' '
+	git push parent1 master:foreign &&
+	diff expected actual
+'
+
+test_expect_success 'add a branch' '
+	git checkout -b other parent1/foreign &&
+	test_commit three
+'
+
+COMMIT3="$(git rev-parse HEAD)"
+export COMMIT3
+
+cat >expected <<EOF
+parent1
+repo1
+refs/heads/other $COMMIT3 refs/heads/foreign $COMMIT2
+EOF
+
+test_expect_success 'push to default' '
+	git push &&
+	diff expected actual
+'
+
+cat >expected <<EOF
+parent1
+repo1
+refs/tags/one $COMMIT1 refs/tags/tag1 $_z40
+HEAD~ $COMMIT2 refs/heads/prev $_z40
+EOF
+
+test_expect_success 'push non-branches' '
+	git push parent1 one:tag1 HEAD~:refs/heads/prev &&
+	diff expected actual
+'
+
+cat >expected <<EOF
+parent1
+repo1
+(delete) $_z40 refs/heads/prev $COMMIT2
+EOF
+
+test_expect_success 'push delete' '
+	git push parent1 :prev &&
+	diff expected actual
+'
+
+cat >expected <<EOF
+repo1
+repo1
+HEAD $COMMIT3 refs/heads/other $_z40
+EOF
+
+test_expect_success 'push to URL' '
+	git push repo1 HEAD &&
+	diff expected actual
+'
+
+# Test that filling pipe buffers doesn't cause failure
+# Too slow to leave enabled for general use
+if false
+then
+	printf 'parent1\nrepo1\n' >expected
+	nr=1000
+	while test $nr -lt 2000
+	do
+		nr=$(( $nr + 1 ))
+		git branch b/$nr $COMMIT3
+		echo "refs/heads/b/$nr $COMMIT3 refs/heads/b/$nr $_z40" >>expected
+	done
+
+	test_expect_success 'push many refs' '
+		git push parent1 "refs/heads/b/*:refs/heads/b/*" &&
+		diff expected actual
+	'
+fi
+
+test_done