racket/gui: fix `slider%' range checking

Closes PR 12669

collects/mred/private/mritem.rkt

@@ -361,7 +361,17 @@
 	  (check-callback cwho callback)
 	  (check-slider-integer cwho init-value)
 	  (check-style cwho '(vertical horizontal) '(plain vertical-label horizontal-label deleted) style)
-	  (check-font cwho font)))
+	  (check-font cwho font)
+          (unless (<= minv maxv)
+            (raise-mismatch-error (who->name cwho) 
+                                  (format "minumum value: ~e is greater than maximum value: " minv)
+                                  maxv))
+          (unless (<= minv init-value maxv)
+            (raise-mismatch-error (who->name cwho) 
+                                  (format "minumum value: ~e and maximum value: ~e do no bound initial value: " 
+                                          minv
+                                          maxv)
+                                  init-value))))
       (private-field
        [wx #f])
       (public

collects/tests/gracket/windowing.rktl

@@ -630,6 +630,10 @@
     (containee-window-tests g #t #f parent frame 2))
 
   (printf "Slider\n")
+  (mismatch
+   (new slider% [parent parent] [label #f] [min-value 10] [max-value 9]))
+  (mismatch
+   (new slider% [parent parent] [label #f] [min-value 10] [max-value 11] [init-value 12]))
   (letrec ([s (make-object slider% 
 			   "&Slider"
 			   -2 8