From a1790819d007237bdac2e5e4419d2922fd4460ab Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 19 Jul 2012 23:32:19 +0530
Subject: [PATCH] ...

---
 src/calibre/gui2/device.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/calibre/gui2/device.py b/src/calibre/gui2/device.py
index 83c71bb129..1dcadf7b65 100644
--- a/src/calibre/gui2/device.py
+++ b/src/calibre/gui2/device.py
@@ -934,6 +934,11 @@ class DeviceMixin(object): # {{{
 
         fmt = None
         if specific:
+            if (not self.device_connected or not self.device_manager or
+                    self.device_manager.device is None):
+                error_dialog(self, _('No device'),
+                        _('No device connected'), show=True)
+                return
             formats = []
             aval_out_formats = available_output_formats()
             format_count = {}