The maildir specification says the following about unique names:
A unique name can be anything that doesn't contain a colon (or
slash) and doesn't start with a dot.
[http://cr.yp.to/proto/maildir.html]
So disallowing a unique name to have a comma breaks maildir import on
systems where there is a comma in the names.
def maildir_data msg
fn = File.basename @ids_to_fns[msg]
- fn =~ %r{^([^:,]+):([12]),([DFPRST]*)$}
+ fn =~ %r{^([^:]+):([12]),([DFPRST]*)$}
[($1 || fn), ($2 || "2"), ($3 || "")]
end