t6022: Add test combinations of {content conflict?, D/F conflict remains?}

Add testing of the various ways that a renamed file to a path involved in
a directory/file conflict may be involved in.  This includes whether or not
there are conflicts of the contents of the renamed file (if the file was
modified on both sides of history), and whether the directory from the
other side of the merge will disappear as a result of the merge or not.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6022-merge-rename.sh

@@ -3,6 +3,11 @@
 test_description='Merge-recursive merging renames'
 . ./test-lib.sh
 
+modify () {
+	sed -e "$1" <"$2" >"$2.x" &&
+	mv "$2.x" "$2"
+}
+
 test_expect_success setup \
 '
 cat >A <<\EOF &&
@@ -341,4 +346,127 @@ test_expect_success 'merge of identical changes in a renamed file' '
 	GIT_MERGE_VERBOSITY=3 git merge change+rename | grep "^Skipped B"
 '
 
+test_expect_success 'setup for rename + d/f conflicts' '
+	git reset --hard &&
+	git checkout --orphan dir-in-way &&
+	git rm -rf . &&
+
+	mkdir sub &&
+	mkdir dir &&
+	printf "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n" >sub/file &&
+	echo foo >dir/file-in-the-way &&
+	git add -A &&
+	git commit -m "Common commmit" &&
+
+	echo 11 >>sub/file &&
+	echo more >>dir/file-in-the-way &&
+	git add -u &&
+	git commit -m "Commit to merge, with dir in the way" &&
+
+	git checkout -b dir-not-in-way &&
+	git reset --soft HEAD^ &&
+	git rm -rf dir &&
+	git commit -m "Commit to merge, with dir removed" -- dir sub/file &&
+
+	git checkout -b renamed-file-has-no-conflicts dir-in-way~1 &&
+	git rm -rf dir &&
+	git rm sub/file &&
+	printf "1\n2\n3\n4\n5555\n6\n7\n8\n9\n10\n" >dir &&
+	git add dir &&
+	git commit -m "Independent change" &&
+
+	git checkout -b renamed-file-has-conflicts dir-in-way~1 &&
+	git rm -rf dir &&
+	git mv sub/file dir &&
+	echo 12 >>dir &&
+	git add dir &&
+	git commit -m "Conflicting change"
+'
+
+printf "1\n2\n3\n4\n5555\n6\n7\n8\n9\n10\n11\n" >expected
+
+test_expect_success 'Rename+D/F conflict; renamed file merges + dir not in way' '
+	git reset --hard &&
+	git checkout -q renamed-file-has-no-conflicts^0 &&
+	git merge --strategy=recursive dir-not-in-way &&
+	git diff --quiet &&
+	test -f dir &&
+	test_cmp expected dir
+'
+
+test_expect_failure 'Rename+D/F conflict; renamed file merges but dir in way' '
+	git reset --hard &&
+	rm -rf dir~* &&
+	git checkout -q renamed-file-has-no-conflicts^0 &&
+	test_must_fail git merge --strategy=recursive dir-in-way >output &&
+
+	grep "CONFLICT (delete/modify): dir/file-in-the-way" output &&
+	grep "Auto-merging dir" output &&
+	grep "Adding as dir~HEAD instead" output &&
+
+	test 2 = "$(git ls-files -u | wc -l)" &&
+	test 2 = "$(git ls-files -u dir/file-in-the-way | wc -l)" &&
+
+	test_must_fail git diff --quiet &&
+	test_must_fail git diff --cached --quiet &&
+
+	test -f dir/file-in-the-way &&
+	test -f dir~HEAD &&
+	test_cmp expected dir~HEAD
+'
+
+cat >expected <<\EOF &&
+1
+2
+3
+4
+5
+6
+7
+8
+9
+10
+<<<<<<< HEAD
+12
+=======
+11
+>>>>>>> dir-not-in-way
+EOF
+
+test_expect_failure 'Rename+D/F conflict; renamed file cannot merge, dir not in way' '
+	git reset --hard &&
+	rm -rf dir~* &&
+	git checkout -q renamed-file-has-conflicts^0 &&
+	test_must_fail git merge --strategy=recursive dir-not-in-way &&
+
+	test 3 = "$(git ls-files -u | wc -l)" &&
+	test 3 = "$(git ls-files -u dir | wc -l)" &&
+
+	test_must_fail git diff --quiet &&
+	test_must_fail git diff --cached --quiet &&
+
+	test -f dir &&
+	test_cmp expected dir
+'
+
+test_expect_failure 'Rename+D/F conflict; renamed file cannot merge and dir in the way' '
+	modify s/dir-not-in-way/dir-in-way/ expected &&
+
+	git reset --hard &&
+	rm -rf dir~* &&
+	git checkout -q renamed-file-has-conflicts^0 &&
+	test_must_fail git merge --strategy=recursive dir-in-way &&
+
+	test 5 = "$(git ls-files -u | wc -l)" &&
+	test 3 = "$(git ls-files -u dir | grep -v file-in-the-way | wc -l)" &&
+	test 2 = "$(git ls-files -u dir/file-in-the-way | wc -l)" &&
+
+	test_must_fail git diff --quiet &&
+	test_must_fail git diff --cached --quiet &&
+
+	test -f dir/file-in-the-way &&
+	test -f dir~HEAD &&
+	test_cmp expected dir~HEAD
+'
+
 test_done