Extend merge-subtree tests to test -Xsubtree=dir.

This tests the configurable -Xsubtree feature of merge-recursive.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t6029-merge-subtree.sh

@@ -52,6 +52,7 @@ test_expect_success 'initial merge' '
 	git merge -s ours --no-commit gui/master &&
 	git read-tree --prefix=git-gui/ -u gui/master &&
 	git commit -m "Merge git-gui as our subdirectory" &&
+	git checkout -b work &&
 	git ls-files -s >actual &&
 	(
 		echo "100644 $o1 0	git-gui/git-gui.sh"
@@ -65,9 +66,10 @@ test_expect_success 'merge update' '
 	echo git-gui2 > git-gui.sh &&
 	o3=$(git hash-object git-gui.sh) &&
 	git add git-gui.sh &&
+	git checkout -b master2 &&
 	git commit -m "update git-gui" &&
 	cd ../git &&
-	git pull -s subtree gui master &&
+	git pull -s subtree gui master2 &&
 	git ls-files -s >actual &&
 	(
 		echo "100644 $o3 0	git-gui/git-gui.sh"
@@ -76,4 +78,47 @@ test_expect_success 'merge update' '
 	test_cmp expected actual
 '
 
+test_expect_success 'initial ambiguous subtree' '
+	cd ../git &&
+	git reset --hard master &&
+	git checkout -b master2 &&
+	git merge -s ours --no-commit gui/master &&
+	git read-tree --prefix=git-gui2/ -u gui/master &&
+	git commit -m "Merge git-gui2 as our subdirectory" &&
+	git checkout -b work2 &&
+	git ls-files -s >actual &&
+	(
+		echo "100644 $o1 0	git-gui/git-gui.sh"
+		echo "100644 $o1 0	git-gui2/git-gui.sh"
+		echo "100644 $o2 0	git.c"
+	) >expected &&
+	test_cmp expected actual
+'
+
+test_expect_success 'merge using explicit' '
+	cd ../git &&
+	git reset --hard master2 &&
+	git pull -Xsubtree=git-gui gui master2 &&
+	git ls-files -s >actual &&
+	(
+		echo "100644 $o3 0	git-gui/git-gui.sh"
+		echo "100644 $o1 0	git-gui2/git-gui.sh"
+		echo "100644 $o2 0	git.c"
+	) >expected &&
+	test_cmp expected actual
+'
+
+test_expect_success 'merge2 using explicit' '
+	cd ../git &&
+	git reset --hard master2 &&
+	git pull -Xsubtree=git-gui2 gui master2 &&
+	git ls-files -s >actual &&
+	(
+		echo "100644 $o1 0	git-gui/git-gui.sh"
+		echo "100644 $o3 0	git-gui2/git-gui.sh"
+		echo "100644 $o2 0	git.c"
+	) >expected &&
+	test_cmp expected actual
+'
+
 test_done