re PR libstdc++/64441 (A match_results returns an incorrect sub_match if the…

re PR libstdc++/64441 (A match_results returns an incorrect sub_match if the sub_match::matched is false)

	PR libstdc++/64441
	* include/bits/regex.tcc (__regex_algo_impl): s/auto/auto&/.
	* include/bits/regex_executor.tcc (_Executor<>::_M_dfs): Likewise.

From-SVN: r219121

libstdc++-v3/ChangeLog

+2014-12-31  Tim Shen  <timshen@google.com>
+
+	PR libstdc++/64441
+	* include/bits/regex.tcc (__regex_algo_impl): s/auto/auto&/.
+	* include/bits/regex_executor.tcc (_Executor<>::_M_dfs): Likewise.
+
 2014-12-28  David Edelsohn  <dje.gcc@gmail.com>
 
 	* testsuite/26_numerics/headers/cmath/c99_classification_macros_c.cc:

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

@@ -96,7 +96,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	}
       if (__ret)
 	{
-	  for (auto __it : __res)
+	  for (auto& __it : __res)
 	    if (!__it.matched)
 	      __it.first = __it.second = __e;
 	  auto& __pre = __res[__res.size()-2];

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

@@ -310,7 +310,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    if (!__submatch.matched)
 	      break;
 	    auto __last = _M_current;
-	    for (auto __tmp = __submatch.first;
+	    for (auto& __tmp = __submatch.first;
 		 __last != _M_end && __tmp != __submatch.second;
 		 ++__tmp)
 	      ++__last;