[MERGE] Reliably encode and decode PermissionDenied and ReadError errors from a smart server

[Andrew Bennetts]

This patch does two main things:

 * Moves the encoding of PermissionDenied (and ReadError) on the server-side into
   the catch-all for all smart request handlers.  This means that any request
   handler that happens to trigger a PermissionDenied will cause a proper
   'PermissionDenied' response on the wire.

 * Adds client-side decoding of PermissionDenied (and ReadError) to
   bzrlib/remote.py.

It also adds a simple __repr__ to BzrError, just because it makes test failures
from assertEqual(exc1, exc2) clearer.

This is a step towards a fix for <https://bugs.launchpad.net/bzr/+bug/278673>,
and probably some other real but unfiled bugs like it.  The rest of the fix will
be posted shortly as a patch that builds on this one.

-Andrew.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: robust-permissiondenied-and-readerror.diff
Type: text/x-diff
Size: 14501 bytes
Desc: not available
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20081029/c524efbd/attachment-0001.bin