Merge pull request #1090 from chrox/fix_869

fix #869

frontend/apps/filemanager/filemanager.lua

@@ -140,6 +140,10 @@ function FileManager:init()
         menu = self.menu
     })
 
+    if Device:hasKeys() then
+        self.key_events.Close = { {"Home"}, doc = "close filemanager" }
+    end
+
     self:handleEvent(Event:new("SetDimensions", self.dimen))
 end
 

frontend/ui/uimanager.lua

@@ -153,6 +153,10 @@ end
 
 -- unregister a widget
 function UIManager:close(widget)
+    if not widget then
+        DEBUG("widget not exist to be closed")
+        return
+    end
     DEBUG("close widget", widget.id)
     Input.disable_double_tap = DGESDETECT_DISABLE_DOUBLE_TAP
     local dirty = false