[Bug libstdc++/43525] New: Useless condition: "if (__x->_M_right != __y)"

[ninive at gmx dot at]

The variable "__y" in _Rb_tree_increment (src/tree.cc) is always equal to
"__x->_M_parent. Therefore the condition means (which is alwys true):

if (__x->_M_right != __x->_M_parent)

The source:

  _Rb_tree_node_base*
  _Rb_tree_increment(_Rb_tree_node_base* __x) throw ()
  {
    if (__x->_M_right != 0) 
      {
        __x = __x->_M_right;
        while (__x->_M_left != 0)
          __x = __x->_M_left;
      }
    else 
      {
        _Rb_tree_node_base* __y = __x->_M_parent;      // y == x->parent
        while (__x == __y->_M_right) 
          {
            __x = __y;
            __y = __y->_M_parent;                 // y == x->parent
          }
        if (__x->_M_right != __y)    // if( x->right != x->parent )
          __x = __y;
      }
    return __x;
  }


-- 
           Summary: Useless condition: "if (__x->_M_right != __y)"
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: ninive at gmx dot at


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43525