Merge lp:~vila/udd/801776-drop-transport into lp:udd

[Vincent Ladeuil]

This makes refresh_possible_transports more robust.

The aim of refresh_possible_transports is to avoid reusing a transport going
stale because it hasn't been used recently and the server closed the
connection.

I've grepped the logs of all packages and the conclusion is that we missed a
bunch of cases where bzrlib raise an exception which really means the
transport is stale and we aborted the import instead of letting the caller
create a new connection.

The proposed version doesn't try to catch all valid exceptions, it logs them
for investigation (time will tell if it's really worth the effort) and just
drop the transport.

If nothing else, this patch will allow the chromium-browser to succeed.

[lp:~vila/udd/801776-drop-transport]

532. By Vincent Ladeuil on 2011-10-24

Get rid of the superfluous try.

[Martin Pool (mbp)]

  vote approve

review: Approve

=== modified file 'udd/icommon.py'
--- udd/icommon.py	2011-10-21 14:17:18 +0000
+++ udd/icommon.py	2011-10-24 10:18:24 +0000
@@ -1650,20 +1650,16 @@
     still_usable = []
     for t in possible_transports:
         try:
-            try:
-                t.has('file-that-does-not-exist')
-            except errors.PathError:
-                # bzrlib isn't supposed to raise this error, but it does.
-                pass
-            except errors.TooManyConcurrentRequests:
-                mutter(
-                    "refresh_possible_transports encountered a smart "
-                    "transport with outstanding request: %r", t)
-        except socket.error, e:
-            # connection has been timed out by the server perhaps.
+            t.has('file-that-does-not-exist')
+        except errors.TooManyConcurrentRequests:
             mutter(
-                "refresh_possible_transports dropping stale transport %r (%s)",
-                t, e)
+                "refresh_possible_transports encountered a smart "
+                "transport with outstanding request: %r", t)
+        except Exception, e:
+            # Any other exception is logged for further investigation. But
+            # whatever it is, the transport can't be reused so we dropt it.
+            mutter("refresh_possible_transports dropping"
+                   " transport %r (%s)", t, e)
         else:
             still_usable.append(t)
     possible_transports[:] = still_usable