From e5de8f4115d5edc76179282d1a03c7a8706f412e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Mon, 3 Jul 2017 23:08:04 +0200
Subject: [PATCH] devices: better handle exceptions in device extension

Do not fail app.save() just because listing devices failed, for any
reason.
---
 qubes/devices.py | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/qubes/devices.py b/qubes/devices.py
index b4d166d2..a3f9783e 100644
--- a/qubes/devices.py
+++ b/qubes/devices.py
@@ -241,8 +241,17 @@ class DeviceCollection(object):
         attached persistently.
         '''
 
-        devices = self._vm.fire_event('device-list-attached:' + self._bus,
-            persistent=persistent)
+        try:
+            devices = self._vm.fire_event('device-list-attached:' + self._bus,
+                persistent=persistent)
+        except Exception as e:  # pylint: disable=broad-except
+            self._vm.log.exception(e, 'Failed to list {} devices'.format(
+                self._bus))
+            if persistent is True:
+                # don't break app.save()
+                return self._set
+            else:
+                raise
         result = set()
         for dev, options in devices:
             if dev in self._set and not persistent: