PR libstdc++/49060

	* include/backward/hashtable.h (hashtable::erase): Don't crash if
	erasing first and another element with a reference to the other
	element.
	* testsuite/backward/hash_set/49060.cc: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@174240 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 7 deletions

diff --git a/libstdc++-v3/include/backward/hashtable.h b/libstdc++-v3/include/backward/hashtable.h
index 0bcaec4fdc2..91b0c602cec 100644
--- a/libstdc++-v3/include/backward/hashtable.h
+++ b/libstdc++-v3/include/backward/hashtable.h
@@ -898,13 +898,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 		  __next = __cur->_M_next;
 		}
 	    }
-	  if (_M_equals(_M_get_key(__first->_M_val), __key))
-	    {
-	      _M_buckets[__n] = __first->_M_next;
-	      _M_delete_node(__first);
-	      ++__erased;
-	      --_M_num_elements;
-	    }
+	  bool __delete_first = _M_equals(_M_get_key(__first->_M_val), __key);
 	  if (__saved_slot)
 	    {
 	      __next = __saved_slot->_M_next;
@@ -913,6 +907,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	      ++__erased;
 	      --_M_num_elements;
 	    }
+	  if (__delete_first)
+	    {
+	      _M_buckets[__n] = __first->_M_next;
+	      _M_delete_node(__first);
+	      ++__erased;
+	      --_M_num_elements;
+	    }
 	}
       return __erased;
     }