From: Tim Shen <timshen@google.com>
Date: Tue, 25 Nov 2014 05:43:04 +0000 (+0000)
Subject: re PR libstdc++/63920 (Any regular expression should not match an empty sequence... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=02ba3fc22d5b4101f99bd5b0cc5101a04cdd0eb2;p=gcc.git

re PR libstdc++/63920 (Any regular expression should not match an empty sequence if match_not_null is specified)

	PR libstdc++/63920
	* include/bits/regex_executor.h: Make _M_begin non const.
	* include/bits/regex_executor.tcc (_Executor<>::_M_search): Increase
	_M_begin in search algorithm, so that _M_begin is treated as
	"current start position" for each search iteration.
	* testsuite/28_regex/algorithms/regex_search/ecma/flags.cc: New
	testcase.

From-SVN: r218037
---

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index c245d26b670..0c4cce9ed36 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,13 @@
+2014-11-25  Tim Shen  <timshen@google.com>
+
+	PR libstdc++/63920
+	* include/bits/regex_executor.h: Make _M_begin non const.
+	* include/bits/regex_executor.tcc (_Executor<>::_M_search): Increase
+	_M_begin in search algorithm, so that _M_begin is treated as
+	"current start position" for each search iteration.
+	* testsuite/28_regex/algorithms/regex_search/ecma/flags.cc: New
+	testcase.
+
 2014-11-21  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR bootstrap/63784
diff --git a/libstdc++-v3/include/bits/regex_executor.h b/libstdc++-v3/include/bits/regex_executor.h
index b26992c9a4b..2d7796fba80 100644
--- a/libstdc++-v3/include/bits/regex_executor.h
+++ b/libstdc++-v3/include/bits/regex_executor.h
@@ -205,7 +205,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     public:
       _ResultsVec                                           _M_cur_results;
       _BiIter                                               _M_current;
-      const _BiIter                                         _M_begin;
+      _BiIter                                               _M_begin;
       const _BiIter                                         _M_end;
       const _RegexT&                                        _M_re;
       const _NFAT&                                          _M_nfa;
diff --git a/libstdc++-v3/include/bits/regex_executor.tcc b/libstdc++-v3/include/bits/regex_executor.tcc
index 38d4781b0c5..a9736675bf6 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -39,17 +39,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     bool _Executor<_BiIter, _Alloc, _TraitsT, __dfs_mode>::
     _M_search()
     {
+      if (_M_search_from_first())
+	return true;
       if (_M_flags & regex_constants::match_continuous)
-	return _M_search_from_first();
-      auto __cur = _M_begin;
-      do
+	return false;
+      _M_flags |= regex_constants::match_prev_avail;
+      while (_M_begin != _M_end)
 	{
-	  _M_current = __cur;
-	  if (_M_main(_Match_mode::_Prefix))
+	  ++_M_begin;
+	  if (_M_search_from_first())
 	    return true;
 	}
-      // Continue when __cur == _M_end
-      while (__cur++ != _M_end);
       return false;
     }
 
diff --git a/libstdc++-v3/testsuite/28_regex/algorithms/regex_search/ecma/flags.cc b/libstdc++-v3/testsuite/28_regex/algorithms/regex_search/ecma/flags.cc
index 45ad0f63e56..6b038ee9333 100644
--- a/libstdc++-v3/testsuite/28_regex/algorithms/regex_search/ecma/flags.cc
+++ b/libstdc++-v3/testsuite/28_regex/algorithms/regex_search/ecma/flags.cc
@@ -65,6 +65,8 @@ test01()
 			     regex_constants::match_prev_avail));
   VERIFY( regex_search_debug("ba"+1, regex("\\Ba"),
 			     regex_constants::match_prev_avail));
+  // PR libstdc++/63920
+  VERIFY(!regex_search_debug("a", regex("b*"), regex_constants::match_not_null));
 }
 
 int