PR c++/12932
	* class.c (currently_open_derived_class): Check if
	current_class_type is NULL_TREE.
	* semantics.c (finish_call_expr): Check if
	currently_open_derived_class returns NULL_TREE.
	* cp-tree.h (DERIVED_FROM_P): Add parenthesis around PARENT
	parameter.

	* g++.dg/template/static5.C: New test.

From-SVN: r73705