re PR libstdc++/83601 (std::regex_replace C++14 conformance issue: escaping in SED mode)

	PR libstdc++/83601
	* include/bits/regex.tcc (regex_replace): Fix escaping in sed.
	* testsuite/28_regex/algorithms/regex_replace/char/pr83601.cc: Tests.
	* testsuite/28_regex/algorithms/regex_replace/wchar_t/pr83601.cc: Tests.

From-SVN: r256654

libstdc++-v3/ChangeLog

+2018-01-13  Tim Shen  <timshen@google.com>
+
+	PR libstdc++/83601
+	* include/bits/regex.tcc (regex_replace): Fix escaping in sed.
+	* testsuite/28_regex/algorithms/regex_replace/char/pr83601.cc: Tests.
+	* testsuite/28_regex/algorithms/regex_replace/wchar_t/pr83601.cc: Tests.
+
 2018-01-12  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	PR libstdc++/64054

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

@@ -373,22 +373,32 @@ namespace __detail
 
       if (__flags & regex_constants::format_sed)
 	{
-	  for (; __fmt_first != __fmt_last;)
-	    if (*__fmt_first == '&')
-	      {
-		__output(0);
-		++__fmt_first;
-	      }
-	    else if (*__fmt_first == '\\')
-	      {
-		if (++__fmt_first != __fmt_last
-		    && __fctyp.is(__ctype_type::digit, *__fmt_first))
-		  __output(__traits.value(*__fmt_first++, 10));
-		else
-		  *__out++ = '\\';
-	      }
-	    else
-	      *__out++ = *__fmt_first++;
+	  bool __escaping = false;
+	  for (; __fmt_first != __fmt_last; __fmt_first++)
+	    {
+	      if (__escaping)
+		{
+		  __escaping = false;
+		  if (__fctyp.is(__ctype_type::digit, *__fmt_first))
+		    __output(__traits.value(*__fmt_first, 10));
+		  else
+		    *__out++ = *__fmt_first;
+		  continue;
+		}
+	      if (*__fmt_first == '\\')
+		{
+		  __escaping = true;
+		  continue;
+		}
+	      if (*__fmt_first == '&')
+		{
+		  __output(0);
+		  continue;
+		}
+	      *__out++ = *__fmt_first;
+	    }
+	  if (__escaping)
+	    *__out++ = '\\';
 	}
       else
 	{

libstdc++-v3/testsuite/28_regex/algorithms/regex_replace/char/pr83601.cc

+// { dg-do run { target c++11 } }
+
+// Copyright (C) 2018 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 <regex>
+#include <testsuite_hooks.h>
+
+// libstdc++/83601
+int main() {
+    auto format = std::regex_constants::format_sed;
+    auto out = regex_replace("ab", std::regex("(a)(b)"), R"(\\1\&\\2)", format);
+    VERIFY(out == R"(\1&\2)");
+
+    return 0;
+}

libstdc++-v3/testsuite/28_regex/algorithms/regex_replace/wchar_t/pr83601.cc

+// { dg-do run { target c++11 } }
+
+// Copyright (C) 2018 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 <regex>
+#include <testsuite_hooks.h>
+
+// libstdc++/83601
+void frep(const wchar_t *istr, const wchar_t *rstr, const wchar_t *ostr) {
+    std::basic_regex<wchar_t> wrgx(L"(a*)(b+)");
+    std::basic_string<wchar_t> wstr = istr, wret = ostr, test;
+    std::regex_replace(std::back_inserter(test), wstr.begin(), wstr.end(),
+                       wrgx, std::basic_string<wchar_t>(rstr),
+                       std::regex_constants::format_sed);
+    VERIFY(test == wret);
+}
+
+int main() {
+    frep(L"xbbyabz", L"!\\\\2!", L"x!\\2!y!\\2!z");
+    frep(L"xbbyabz", L"!\\\\0!", L"x!\\0!y!\\0!z");
+    frep(L"xbbyabz", L"!\\&!", L"x!&!y!&!z");
+    return 0;
+}