Add test case for update hooks in receive-pack.

Verify that the update hooks work as documented/advertised.  This is
a simple set of tests to check that the update hooks run with the
parameters expected, have their STDOUT and STDERR redirected to
the client side of the connection, and that their STDIN does not
contain any data (as its actually /dev/null).
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

t/t5401-update-hooks.sh

+#!/bin/sh
+#
+# Copyright (c) 2006 Shawn O. Pearce
+#
+
+test_description='Test the update hook infrastructure.'
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo This is a test. >a &&
+	git-update-index --add a &&
+	tree0=$(git-write-tree) &&
+	commit0=$(echo setup | git-commit-tree $tree0) &&
+	git-update-ref HEAD $commit0 &&
+	git-clone ./. victim &&
+	echo We hope it works. >a &&
+	git-update-index a &&
+	tree1=$(git-write-tree) &&
+	commit1=$(echo modify | git-commit-tree $tree1 -p $commit0) &&
+	git-update-ref HEAD $commit1
+'
+
+cat >victim/.git/hooks/update <<'EOF'
+#!/bin/sh
+echo "$@" >$GIT_DIR/update.args
+read x; echo -n "$x" >$GIT_DIR/update.stdin
+echo STDOUT update
+echo STDERR update >&2
+EOF
+chmod u+x victim/.git/hooks/update
+
+cat >victim/.git/hooks/post-update <<'EOF'
+#!/bin/sh
+echo "$@" >$GIT_DIR/post-update.args
+read x; echo -n "$x" >$GIT_DIR/post-update.stdin
+echo STDOUT post-update
+echo STDERR post-update >&2
+EOF
+chmod u+x victim/.git/hooks/post-update
+
+test_expect_success push '
+	git-send-pack ./victim/.git/ master >send.out 2>send.err
+'
+
+test_expect_success 'hooks ran' '
+	test -f victim/.git/update.args &&
+	test -f victim/.git/update.stdin &&
+	test -f victim/.git/post-update.args &&
+	test -f victim/.git/post-update.stdin
+'
+
+test_expect_success 'update hook arguments' '
+	echo refs/heads/master $commit0 $commit1 |
+	diff -u - victim/.git/update.args
+'
+
+test_expect_success 'post-update hook arguments' '
+	echo refs/heads/master |
+	diff -u - victim/.git/post-update.args
+'
+
+test_expect_failure 'update hook stdin is /dev/null' '
+	test -s victim/.git/update.stdin
+'
+
+test_expect_failure 'post-update hook stdin is /dev/null' '
+	test -s victim/.git/post-update.stdin
+'
+
+test_expect_failure 'send-pack produced no output' '
+	test -s send.out
+'
+
+test_expect_success 'send-pack stderr contains hook messages' '
+	grep "STDOUT update" send.err &&
+	grep "STDERR update" send.err &&
+	grep "STDOUT post-update" send.err &&
+	grep "STDERR post-update" send.err
+'
+
+test_done