racket/gui: fix reparent' with a pane%' target

collects/mred/private/wxpanel.rkt

@@ -55,7 +55,8 @@
 	[get-x (lambda () pos-x)]
 	[get-y (lambda () pos-y)]
 	[get-width (lambda () width)]
-	[get-height (lambda () height)])
+	[get-height (lambda () height)]
+        [adopt-child (lambda (c) (send (get-parent) adopt-child c))])
       (sequence (super-init))))
 
   (define tab-h-border (if (eq? (system-type) 'unix)

collects/tests/gracket/item.rkt

@@ -519,7 +519,10 @@
 		   (let ([v (send c get-selection)])
 		     (when (positive? v)
                        (define f (new frame% [label "New Parent"]))
-		       (send (list-ref items (sub1 v)) reparent f)
+                       (define p (if (zero? (random 2))
+                                     (new vertical-pane% [parent f])
+                                     f))
+		       (send (list-ref items (sub1 v)) reparent p)
                        (send f show #t)
 		       (send c set-selection 0)))))
     (cons (make-object popup-test-canvas%