seahorse sucks CPU, and RAM, causes swap storm, makes system completely unresponsive

Binary package hint: seahorse

I've been attempting to get "bzr viz" to show GPG signatures on revisions. So, I ran "bzr viz" against a small local branch (or a branch from http://bazaar.launchpad.net/~bzr/bzr-stats/trunk/), selected various revisions, and also selected the "Signature" tab. Most of the time, bzr-gtk will simply say "Signature key not available" (that seems like another bug...) when switching to view a revision with a signature. However, sometimes, bzr-gtk will hang, and after a few seconds spew the following backtrace:

[swarren@esk test1]$ bzr viz
No handlers could be found for logger "bzr"
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/gtk/revisionview.py", line 486, in _switch_page_cb
    self.signature_table.set_revision(self._revision)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/gtk/revisionview.py", line 210, in set_revision
    self.show_signature(crypttext)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/gtk/revisionview.py", line 229, in show_signature
    (cleartext, key) = seahorse.verify(crypttext)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/gtk/seahorse.py", line 83, in verify
    keyset[key] = Key(key)
  File "/usr/lib/python2.6/dist-packages/bzrlib/plugins/gtk/seahorse.py", line 99, in __init__
    fields = openpgp.GetKeyFields(key, ['fingerprint', 'trust', 'flags', 'display-name', 'location'])
  File "/var/lib/python-support/python2.6/dbus/proxies.py", line 140, in __call__
    **keywords)
  File "/var/lib/python-support/python2.6/dbus/connection.py", line 622, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Right after this happens, seahorse-agent (or seahorse-daemon, whichever it is) will start sucking a lot of CPU, and also growing its RAM usage very fast. If it isn't killed quickly, it'll consume all physical RAM and grow into swap. The CPU usage and resulting swap storm make the system almost entirely unresponsive; even switching VTs and text-mode login doesn't work. Sometimes, switching VTs and CTRL-ALT-DEL will gracefully restart. (As an aside, epic fail for the kernel; OOM killer ended up killing some completely irrelevant and tiny Apache process, then not bothering to ever kill anything else, like the runaway seahorse process)

Final note: I have the WAR from https://bugzilla.gnome.org/attachment.cgi?id=135042&action=edit applied, so as to avoid https://bugs.launchpad.net/bzr-gtk/+bug/377476. I don't expect this makes a difference, but you never know.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
NonfreeKernelModules: nvidia
Package: seahorse 2.26.1-0ubuntu1 [modified: usr/share/dbus-1/services/org.gnome.seahorse.service]
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
SourcePackage: seahorse
Uname: Linux 2.6.28-15-generic i686