(svn r17440) -Fix [FS#3179] (r17375): long scrollbars would scroll when that was not intended. They would also not properly mark the window dirty.

src/widgets/dropdown.cpp

@@ -190,6 +190,8 @@ struct DropdownWindow : Window {
 	virtual void OnTick()
 	{
 		this->vscroll.UpdatePosition(this->scrolling);
+		this->scrolling = 0;
+		this->SetDirty();
 	}
 
 	virtual void OnMouseLoop()