Merge branch 'jc/maint-1.6.0-read-tree-overlay' into maint

* jc/maint-1.6.0-read-tree-overlay:
  read-tree A B C: do not create a bogus index and do not segfault

t/t1008-read-tree-overlay.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+
+test_description='test multi-tree read-tree without merging'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo one >a &&
+	git add a &&
+	git commit -m initial &&
+	git tag initial &&
+	echo two >b &&
+	git add b &&
+	git commit -m second &&
+	git checkout -b side initial &&
+	echo three >a &&
+	mkdir b &&
+	echo four >b/c &&
+	git add b/c &&
+	git commit -m third
+'
+
+test_expect_success 'multi-read' '
+	git read-tree initial master side &&
+	(echo a; echo b/c) >expect &&
+	git ls-files >actual &&
+	test_cmp expect actual
+'
+
+test_done
+