commit 5218b515fdb54881d8a2b87c28eb5fd84c52db01
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Sep 27 16:22:28 2016 +0100

    Fix lifetime of mutex lock in debug iterator
    
    	* include/debug/safe_iterator.h (_Safe_iterator::operator++()): Fix
    	lifetime of lock.

diff --git a/libstdc++-v3/include/debug/safe_iterator.h b/libstdc++-v3/include/debug/safe_iterator.h
index 5368f3b..3f5a7f8 100644
--- a/libstdc++-v3/include/debug/safe_iterator.h
+++ b/libstdc++-v3/include/debug/safe_iterator.h
@@ -296,7 +296,7 @@ namespace __gnu_debug
 	_GLIBCXX_DEBUG_VERIFY(this->_M_incrementable(),
 			      _M_message(__msg_bad_inc)
 			      ._M_iterator(*this, "this"));
-	__gnu_cxx::__scoped_lock(this->_M_get_mutex());
+	__gnu_cxx::__scoped_lock __l(this->_M_get_mutex());
 	++base();
 	return *this;
       }