t7505: add tests for cherry-pick and rebase -i/-p

Check that cherry-pick and rebase call the 'prepare-commit-msg' hook
correctly. The expected values for the hook arguments are taken to
match the current master branch. I think there is scope for improving
the arguments passed so they make a bit more sense - for instance
cherry-pick currently passes different arguments depending on whether
the commit message is being edited. Also the arguments for rebase
could be improved. Commit 7c4188360a ("rebase -i: proper
prepare-commit-msg hook argument when squashing", 2008-10-3) apparently
changed things so that when squashing rebase would pass 'squash' as
the argument to the hook but that has been lost.

I think that it would make more sense to pass 'message' for revert and
cherry-pick -x/-s (i.e. cases where there is a new message or the
current message in modified by the command), 'squash' when squashing
with a new message and 'commit HEAD/CHERRY_PICK_HEAD'
otherwise (picking and squashing without a new message).

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7505-prepare-commit-msg-hook.sh

@@ -4,6 +4,38 @@ test_description='prepare-commit-msg hook'
 
 . ./test-lib.sh
 
+test_expect_success 'set up commits for rebasing' '
+	test_commit root &&
+	test_commit a a a &&
+	test_commit b b b &&
+	git checkout -b rebase-me root &&
+	test_commit rebase-a a aa &&
+	test_commit rebase-b b bb &&
+	for i in $(test_seq 1 13)
+	do
+		test_commit rebase-$i c $i
+	done &&
+	git checkout master &&
+
+	cat >rebase-todo <<-EOF
+	pick $(git rev-parse rebase-a)
+	pick $(git rev-parse rebase-b)
+	fixup $(git rev-parse rebase-1)
+	fixup $(git rev-parse rebase-2)
+	pick $(git rev-parse rebase-3)
+	fixup $(git rev-parse rebase-4)
+	squash $(git rev-parse rebase-5)
+	reword $(git rev-parse rebase-6)
+	squash $(git rev-parse rebase-7)
+	fixup $(git rev-parse rebase-8)
+	fixup $(git rev-parse rebase-9)
+	edit $(git rev-parse rebase-10)
+	squash $(git rev-parse rebase-11)
+	squash $(git rev-parse rebase-12)
+	edit $(git rev-parse rebase-13)
+	EOF
+'
+
 test_expect_success 'with no hook' '
 
 	echo "foo" > file &&
@@ -31,19 +63,41 @@ mkdir -p "$HOOKDIR"
 echo "#!$SHELL_PATH" > "$HOOK"
 cat >> "$HOOK" <<'EOF'
 
+GIT_DIR=$(git rev-parse --git-dir)
+if test -d "$GIT_DIR/rebase-merge"
+then
+	rebasing=1
+else
+	rebasing=0
+fi
+
+get_last_cmd () {
+	tail -n1 "$GIT_DIR/rebase-merge/done" | {
+		read cmd id _
+		git log --pretty="[$cmd %s]" -n1 $id
+	}
+}
+
 if test "$2" = commit
 then
-	source=$(git rev-parse "$3")
+	if test $rebasing = 1
+	then
+		source="$3"
+	else
+		source=$(git rev-parse "$3")
+	fi
 else
 	source=${2-default}
 fi
-if test "$GIT_EDITOR" = :
+test "$GIT_EDITOR" = : && source="$source (no editor)"
+
+if test $rebasing = 1
 then
-	sed -e "1s/.*/$source (no editor)/" "$1" >msg.tmp
+	echo "$source $(get_last_cmd)" >"$1"
 else
 	sed -e "1s/.*/$source/" "$1" >msg.tmp
+	mv msg.tmp "$1"
 fi
-mv msg.tmp "$1"
 exit 0
 EOF
 chmod +x "$HOOK"
@@ -158,6 +212,63 @@ test_expect_success 'with hook and editor (merge)' '
 	test "$(git log -1 --pretty=format:%s)" = "merge"
 '
 
+test_rebase () {
+	expect=$1 &&
+	mode=$2 &&
+	test_expect_$expect C_LOCALE_OUTPUT "with hook (rebase $mode)" '
+		test_when_finished "\
+			git rebase --abort
+			git checkout -f master
+			git branch -D tmp" &&
+		git checkout -b tmp rebase-me &&
+		GIT_SEQUENCE_EDITOR="cp rebase-todo" &&
+		GIT_EDITOR="\"$FAKE_EDITOR\"" &&
+		(
+			export GIT_SEQUENCE_EDITOR GIT_EDITOR &&
+			test_must_fail git rebase $mode b &&
+			echo x >a &&
+			git add a &&
+			test_must_fail git rebase --continue &&
+			echo x >b &&
+			git add b &&
+			git commit &&
+			git rebase --continue &&
+			echo y >a &&
+			git add a &&
+			git commit &&
+			git rebase --continue &&
+			echo y >b &&
+			git add b &&
+			git rebase --continue
+		) &&
+		if test $mode = -p # reword amended after pick
+		then
+			n=18
+		else
+			n=17
+		fi &&
+		git log --pretty=%s -g -n$n HEAD@{1} >actual &&
+		test_cmp "$TEST_DIRECTORY/t7505/expected-rebase$mode" actual
+	'
+}
+
+test_rebase failure -i
+test_rebase failure -p
+
+test_expect_failure 'with hook (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	git cherry-pick rebase-1 &&
+	test "$(git log -1 --pretty=format:%s)" = "message (no editor)"
+'
+
+test_expect_success 'with hook and editor (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	git cherry-pick -e rebase-1 &&
+	test "$(git log -1 --pretty=format:%s)" = merge
+'
+
 cat > "$HOOK" <<'EOF'
 #!/bin/sh
 exit 1
@@ -199,4 +310,11 @@ test_expect_success 'with failing hook (merge)' '
 
 '
 
+test_expect_failure C_LOCALE_OUTPUT 'with failing hook (cherry-pick)' '
+	test_when_finished "git checkout -f master" &&
+	git checkout -B other b &&
+	test_must_fail git cherry-pick rebase-1 2>actual &&
+	test $(grep -c prepare-commit-msg actual) = 1
+'
+
 test_done

t/t7505/expected-rebase-i

@@ -0,0 +1,17 @@
+message [edit rebase-13]
+message (no editor) [edit rebase-13]
+message [squash rebase-12]
+message (no editor) [squash rebase-11]
+default [edit rebase-10]
+message (no editor) [edit rebase-10]
+message [fixup rebase-9]
+message (no editor) [fixup rebase-8]
+message (no editor) [squash rebase-7]
+message [reword rebase-6]
+message [squash rebase-5]
+message (no editor) [fixup rebase-4]
+message (no editor) [pick rebase-3]
+message (no editor) [fixup rebase-2]
+message (no editor) [fixup rebase-1]
+merge [pick rebase-b]
+message [pick rebase-a]

t/t7505/expected-rebase-p

@@ -0,0 +1,18 @@
+message [edit rebase-13]
+message (no editor) [edit rebase-13]
+message [squash rebase-12]
+message (no editor) [squash rebase-11]
+default [edit rebase-10]
+message (no editor) [edit rebase-10]
+message [fixup rebase-9]
+message (no editor) [fixup rebase-8]
+message (no editor) [squash rebase-7]
+HEAD [reword rebase-6]
+message (no editor) [reword rebase-6]
+message [squash rebase-5]
+message (no editor) [fixup rebase-4]
+message (no editor) [pick rebase-3]
+message (no editor) [fixup rebase-2]
+message (no editor) [fixup rebase-1]
+merge [pick rebase-b]
+message [pick rebase-a]