[VM] vm-subject-ignored-prefix used by vm-mark-messages-same-subject?

[Daniel Barrett]

When marking all messages with the same subject (M-S to run
vm-mark-messages-same-subject), I see that messages beginning with
"Re:" are considered the same subject, but those beginning with "Fwd:"
are not. I've tried changing this behavior by customizing the variable
vm-subject-ignored-prefix, since it seems to be the reason:

- vm-mark.el defines vm-mark-or-unmark-messages-same-subject
-- which calls vm-so-sortable-subject
---- which references vm-subject-ignored-prefix

However, when I customize vm-subject-ignored-prefix, the change has no
effect on marking by subject, even if I set the value to nil. The original
value is:

"^\\(re: *\\)+"

I've tried customizing it to be:

"^\\(\\(fwd\\|re\\): *\\)+" ; "fwd" and "re" both
"^\\(fwd: *\\)+" ; just "fwd"
nil ; should disable

None of these changes the behavior from just processing "Re:".
Am I doing something wrong?

I've tried both "easy customization" within Emacs, and changing my
~/.vm file config file.

This is VM 8.2.0b.

Thanks!

--
Dan Barrett
***@blazemonger.com