Index: include/ext/rc_string_base.h
===================================================================
--- include/ext/rc_string_base.h	(revision 155132)
+++ include/ext/rc_string_base.h	(working copy)
@@ -231,8 +231,13 @@
         static _CharT*
         _S_construct_aux(_Integer __beg, _Integer __end,
 			 const _Alloc& __a, std::__true_type)
-	{ return _S_construct(static_cast<size_type>(__beg), __end, __a); }
+	{ return _S_construct_aux_2(static_cast<size_type>(__beg),
+				    __end, __a); }
 
+      static _CharT*
+      _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a)
+      { return _S_construct(__req, __c, __a); }
+
       template<typename _InIterator>
         static _CharT*
         _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a)
Index: include/ext/sso_string_base.h
===================================================================
--- include/ext/sso_string_base.h	(revision 155132)
+++ include/ext/sso_string_base.h	(working copy)
@@ -106,8 +106,12 @@
       template<typename _Integer>
         void
         _M_construct_aux(_Integer __beg, _Integer __end, std::__true_type)
-	{ _M_construct(static_cast<size_type>(__beg), __end); }
+	{ _M_construct_aux_2(static_cast<size_type>(__beg), __end); }
 
+      void
+      _M_construct_aux_2(size_type __req, _CharT __c)
+      { _M_construct(__req, __c); }
+
       template<typename _InIterator>
         void
         _M_construct(_InIterator __beg, _InIterator __end)
Index: include/bits/basic_string.h
===================================================================
--- include/bits/basic_string.h	(revision 155132)
+++ include/bits/basic_string.h	(working copy)
@@ -1588,8 +1588,13 @@
         static _CharT*
         _S_construct_aux(_Integer __beg, _Integer __end,
 			 const _Alloc& __a, __true_type)
-        { return _S_construct(static_cast<size_type>(__beg), __end, __a); }
+        { return _S_construct_aux_2(static_cast<size_type>(__beg),
+				    __end, __a); }
 
+      static _CharT*
+      _S_construct_aux_2(size_type __req, _CharT __c, const _Alloc& __a)
+      { return _S_construct(__req, __c, __a); }
+
       template<class _InIterator>
         static _CharT*
         _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a)
Index: testsuite/21_strings/basic_string/cons/wchar_t/42261.cc
===================================================================
--- testsuite/21_strings/basic_string/cons/wchar_t/42261.cc	(revision 0)
+++ testsuite/21_strings/basic_string/cons/wchar_t/42261.cc	(revision 0)
@@ -0,0 +1,35 @@
+// Copyright (C) 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+#include <testsuite_hooks.h>
+
+// libstdc++/42261
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  using namespace std;
+
+  const wstring s(wstring::size_type(6), wstring::size_type(L'f'));
+  VERIFY( s == L"ffffff" );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
Index: testsuite/21_strings/basic_string/cons/char/42261.cc
===================================================================
--- testsuite/21_strings/basic_string/cons/char/42261.cc	(revision 0)
+++ testsuite/21_strings/basic_string/cons/char/42261.cc	(revision 0)
@@ -0,0 +1,35 @@
+// Copyright (C) 2009 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <string>
+#include <testsuite_hooks.h>
+
+// libstdc++/42261
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  using namespace std;
+
+  const string s(string::size_type(6), string::size_type('f'));
+  VERIFY( s == "ffffff" );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
Index: config/abi/pre/gnu.ver
===================================================================
--- config/abi/pre/gnu.ver	(revision 155131)
+++ config/abi/pre/gnu.ver	(working copy)
@@ -1039,9 +1039,11 @@
     _ZNKSbIwSt11char_traitsIwESaIwEE7crbeginEv;
     _ZNKSbIwSt11char_traitsIwESaIwEE5crendEv;
 
-    # string|wstring ::_S_construct<> helpers
+    # string|wstring ::_S_construct<> and ::_S_construct_aux_2 helpers
     _ZNSs12_S_constructI*;
     _ZNSbIwSt11char_traitsIwESaIwEE12_S_constructI*;
+    _ZNSs18_S_construct_aux_2*;
+    _ZNSbIwSt11char_traitsIwESaIwEE18_S_construct_aux_2*;
 
 } GLIBCXX_3.4.13;
 
