re PR libstdc++/31401 (string find behaves strange when searching from npos)

2007-03-30  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/31401
	* include/bits/basic_string.tcc (find(const _CharT*, size_type,
	size_type)): Avoid unsigned overflow.
	* testsuite/21_strings/basic_string/find/char/4.cc: New.
	* testsuite/21_strings/basic_string/find/wchar_t/4.cc: Likewise.

From-SVN: r123361

libstdc++-v3/ChangeLog

+2007-03-30  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/31401
+	* include/bits/basic_string.tcc (find(const _CharT*, size_type,
+	size_type)): Avoid unsigned overflow.
+	* testsuite/21_strings/basic_string/find/char/4.cc: New.
+	* testsuite/21_strings/basic_string/find/wchar_t/4.cc: Likewise.
+
 2007-03-27  Paolo Carlini  <pcarlini@suse.de>
 
 	* include/bits/fstream.tcc (basic_filebuf<>::underflow):

libstdc++-v3/include/bits/basic_string.tcc

@@ -727,7 +727,7 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
 
       if (__n <= __size)
 	{
-	  for (; __pos + __n <= __size; ++__pos)
+	  for (; __pos <= __size - __n; ++__pos)
 	    if (traits_type::eq(__data[__pos], __s[0])
 		&& traits_type::compare(__data + __pos + 1,
 					__s + 1, __n - 1) == 0)

libstdc++-v3/testsuite/21_strings/basic_string/find/char/4.cc

+// 2007-03-30  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2007 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// 21.3.6.1 basic_string find
+
+#include <string>
+#include <testsuite_hooks.h>
+
+// libstdc++/31401
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  typedef std::string::size_type csize_type;
+  csize_type npos = std::string::npos;
+
+  std::string use = "anu";
+  csize_type pos1 = use.find("a", npos);
+
+  VERIFY( pos1 == npos );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}

libstdc++-v3/testsuite/21_strings/basic_string/find/wchar_t/4.cc

+// 2007-03-30  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2007 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// 21.3.6.1 basic_string find
+
+#include <string>
+#include <testsuite_hooks.h>
+
+// libstdc++/31401
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  typedef std::wstring::size_type csize_type;
+  csize_type npos = std::wstring::npos;
+
+  std::wstring use = L"anu";
+  csize_type pos1 = use.find(L"a", npos);
+
+  VERIFY( pos1 == npos );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}