Merge lp:~marcustomlinson/update-manager/update-manager into lp:update-manager

[Marcus Tomlinson]

Fix hang (LP: #1874591) and crash (LP: #1880987) in snap updates.

[lp:~marcustomlinson/update-manager/update-manager]

2890. By Marcus Tomlinson on 2020-05-28

Fix hang (LP: #1874591) and crash (LP: #1880987) in snap updates

[Brian Murray (brian-murray)]

Thanks for the crash fix, I should have put some more effort into thinking about how to fix it!

review: Approve

=== modified file 'UpdateManager/backend/__init__.py'
--- UpdateManager/backend/__init__.py	2020-04-23 15:17:55 +0000
+++ UpdateManager/backend/__init__.py	2020-05-28 09:38:10 +0000
@@ -113,8 +113,10 @@
                 self.window_main.cache._initDepCache()
             cache = self.window_main.cache
         except Exception as e:
+            # just return an empty array for now, it's perfectly safe to
+            # postpone this duplicates check to a later update.
             logging.debug("error reading cache (%s)" % e)
-            cache = None
+            return []
 
         duplicates = []
         seeded_snaps, _ = self.get_snap_seeds()
@@ -301,7 +303,8 @@
         #close_after_install = False
 
         if action == self.ACTION_INSTALL:
-            if success and os.path.exists("/usr/bin/snap"):
+            if (success and os.path.exists("/usr/bin/snap")
+               and hasattr(self, 'pane_update_progress')):
                 Thread(target=self.update_snaps).start()
             elif success:
                 self.window_main.start_available()
@@ -315,7 +318,8 @@
         else:
             if error_string:
                 self.window_main.start_error(True, error_string, error_desc)
-            elif success and os.path.exists("/usr/bin/snap"):
+            elif (success and os.path.exists("/usr/bin/snap")
+                  and hasattr(self, 'pane_update_progress')):
                 self.window_main.duplicate_packages = self.get_deb2snap_dups()
                 self.window_main.start_available()
             else:
 
=== modified file 'debian/changelog'
--- debian/changelog	2020-05-27 20:29:41 +0000
+++ debian/changelog	2020-05-28 09:38:10 +0000
@@ -1,3 +1,10 @@
+update-manager (1:20.04.12) groovy; urgency=medium
+
+  * Fix hang in apturl-gtk. (LP: #1874591)
+  * Fix crash in snap updates when refreshing the cache fails. (LP: #1880987)
+
+ -- Marcus Tomlinson <[e-mail]>  Thu, 28 May 2020 10:11:51 +0100
+
 update-manager (1:20.04.11) groovy; urgency=medium
 
   * UpdateManager/UpdateManager.py: when refreshing the cache and encountering