Merge to upstream r225300.

Change-Id: I2b23715db9ac129ff80aa78ad5824db0a4d6fbb3

test/std/input.output/string.streams/stringbuf/stringbuf.virtuals/setbuf.pass.cpp

@@ -0,0 +1,32 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <sstream>
+
+// template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
+// class basic_stringbuf
+
+// basic_streambuf<charT,traits>* setbuf(charT* s, streamsize n);
+
+#include <sstream>
+#include <cassert>
+
+int main()
+{
+    {
+        std::stringbuf sb("0123456789");
+        assert(sb.pubsetbuf(0, 0) == &sb);
+        assert(sb.str() == "0123456789");
+    }
+    {
+        std::wstringbuf sb(L"0123456789");
+        assert(sb.pubsetbuf(0, 0) == &sb);
+        assert(sb.str() == L"0123456789");
+    }
+}