+;;;; slot-missing for non-standard classes on SLOT-VALUE
+;;;;
+;;;; FIXME: This is arguably not right, actually: CLHS seems to say
+;;;; we should just signal an error at least for built-in classes, but
+;;;; for a while we were hitting NO-APPLICABLE-METHOD, which is definitely
+;;;; wrong -- so test this for now at least.
+
+(defvar *magic-symbol* (gensym "MAGIC"))
+
+(set *magic-symbol* 42)
+
+(defmethod slot-missing (class instance (slot-name (eql *magic-symbol*)) op
+ &optional new)
+ (if (eq 'setf op)
+ (setf (symbol-value *magic-symbol*) new)
+ (symbol-value *magic-symbol*)))
+
+(assert (eql 42 (slot-value (cons t t) *magic-symbol*)))
+(assert (eql 13 (setf (slot-value 123 *magic-symbol*) 13)))
+(assert (eql 13 (slot-value 'foobar *magic-symbol*)))
+
+;;;; Built-in structure and condition layouts should have NIL in
+;;;; LAYOUT-FOR-STD-CLASS-P, and classes should have T.
+
+(assert (not (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'warning))))
+(assert (not (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'hash-table))))
+(assert (eq t (sb-pcl::layout-for-std-class-p (sb-pcl::find-layout 'standard-object))))