add rebase patch id tests

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3419-rebase-patch-id.sh

@@ -0,0 +1,109 @@
+#!/bin/bash
+
+test_description='git rebase - test patch id computation'
+
+. ./test-lib.sh
+
+test_set_prereq NOT_EXPENSIVE
+test -n "$GIT_PATCHID_TIMING_TESTS" && test_set_prereq EXPENSIVE
+test -x /usr/bin/time && test_set_prereq USR_BIN_TIME
+
+count()
+{
+	i=0
+	while test $i -lt $1
+	do
+		echo "$i"
+		i=$(($i+1))
+	done
+}
+
+scramble()
+{
+	i=0
+	while read x
+	do
+		if test $i -ne 0
+		then
+			echo "$x"
+		fi
+		i=$(((i+1) % 10))
+	done < "$1" > "$1.new"
+	mv -f "$1.new" "$1"
+}
+
+run()
+{
+	echo \$ "$@"
+	/usr/bin/time "$@" >/dev/null
+}
+
+test_expect_success 'setup' '
+	git commit --allow-empty -m initial
+	git tag root
+'
+
+do_tests()
+{
+	pr=$1
+	nlines=$2
+
+	test_expect_success $pr "setup: $nlines lines" "
+		rm -f .gitattributes &&
+		git checkout -q -f master &&
+		git reset --hard root &&
+		count $nlines >file &&
+		git add file &&
+		git commit -q -m initial &&
+		git branch -f other &&
+
+		scramble file &&
+		git add file &&
+		git commit -q -m 'change big file' &&
+
+		git checkout -q other &&
+		: >newfile &&
+		git add newfile &&
+		git commit -q -m 'add small file' &&
+
+		git cherry-pick master >/dev/null 2>&1
+	"
+
+	test_debug "
+		run git diff master^\!
+	"
+
+	test_expect_success $pr 'setup attributes' "
+		echo 'file binary' >.gitattributes
+	"
+
+	test_debug "
+		run git format-patch --stdout master &&
+		run git format-patch --stdout --ignore-if-in-upstream master
+	"
+
+	test_expect_success $pr 'detect upstream patch' "
+		git checkout -q master &&
+		scramble file &&
+		git add file &&
+		git commit -q -m 'change big file again' &&
+		git checkout -q other^{} &&
+		git rebase master &&
+		test_must_fail test -n \"\$(git rev-list master...HEAD~)\"
+	"
+
+	test_expect_success $pr 'do not drop patch' "
+		git branch -f squashed master &&
+		git checkout -q -f squashed &&
+		git reset -q --soft HEAD~2 &&
+		git commit -q -m squashed &&
+		git checkout -q other^{} &&
+		test_must_fail git rebase squashed &&
+		rm -rf .git/rebase-apply
+	"
+}
+
+do_tests NOT_EXPENSIVE 500
+do_tests EXPENSIVE 50000
+
+test_done