PR 15519
	* cp-namespace.c (find_symbol_in_baseclass): Call
	cp_lookup_symbol_in_namespace instead of cp_lookup_symbol_namespace.
	Check result of call to lookup_symbol_static.
	Call lookup_static_symbol_aux unconditionally.
	Call check_typedef on base types before accessing them.
	(cp_lookup_nested_symbol): Fix comment.

	testsuite/
	* gdb.cp/derivation2.cc: New file.
	* gdb.cp/derivation.cc (main): Call foo2.
	* gdb.cp/derivation.exp: Add tests for typedefs in another
	file, and when there's an active block.