...

original commit: cc5768959b1d536ce936b2dd085bc1b8369e80fa

collects/framework/private/panel.ss

@@ -182,14 +182,14 @@
       ;; type percentage : (make-percentage number)
       (define-struct percentage (%))
       
-      (define dragable<%>
+      (define vertical-dragable<%>
         (interface ((class->interface vertical-panel%))
           after-percentage-change
           set-percentages
           get-percentages))
 
       (define vertical-dragable-mixin
-        (mixin ((class->interface vertical-panel%)) (dragable<%>)
+        (mixin ((class->interface vertical-panel%)) (vertical-dragable<%>)
           (init parent)
           (super-instantiate (parent))
           (inherit get-client-size container-flow-modified)

collects/framework/private/sig.ss

@@ -53,6 +53,7 @@
      single-pane%
      ;;multi-view%
 
+     vertical-dragable<%>
      vertical-dragable-mixin
      vertical-dragable%))