[Mailman-Developers] Puzzling doubled-period bug

[A.M. Kuchling]

I've run into a puzzling problem that I can't yet reproduce: our
Mailman installation sometimes doubles periods in the HTML portion of
a message, sometimes breaking a link or image as a result.  Does
anyone recall seeing this before?

For example, here's the difference between the HTML before it's sent
and after it's received:

-> diff old new
60c60
< ational_Conference.gif" alt=3D"2010 National Conference" width=3D"235" =
---
> ational_Conference..gif" alt=3D"2010 National Conference" width=3D"235" =
105c105
< must-attend conference. </p>
---
> must-attend conference.. </p>

The first hunk is a change to an IMG SRC, so it breaks the display.
These are the only two changes in an HTML file that is hundreds of
lines long.  Not every '.' is doubled, and '.' isn't even special to
quoted-printable encoding, so this is very puzzling.  Does this
description sound even vaguely familiar to anyone?

Searches of the Launchpad bug tracker (and bugs.python.org) didn't
turn up anything apparently relevant.  I'll be chasing this down,
since it might be a bug in Mailman, our customization of Mailman, our
spam filtering, or in Python 2.5.0's email package, binascii module,
or somewhere like that.  (For historical reasons, we're stuck with
Python 2.5.0, so possibly this is fixed in 2.5.4).

--amk