[balsa] "Merge threads with same subject" not working

Happy New Year all,

I have a mailbox for messages from a bugtracker. Under normal
circumstances, if I received all the messages about one bug through the
application’s mailing list, all replies are properly threaded under the
initial bug message. However, in many cases, I’ve long since deleted
the original, but now have multiple subsequent messages about some
bug. I do have threading on, but with or without “Merge threads with
the same subject” these messages are not threaded together, even if
they are adjacent when the mailbox is sorted by Subject or Date. I
suppose I can try to create a sample mbox which demonstrates the
problem, and I’ll be glad to provide a screen-shot, if it would help.

Is there some setting I might be missing? Is there any debugging I
could do? Should I open a new issue?

Thanks for any suggestions or advice.

Jack

(This is also a test of creating a new Discourse topic by sending an
email. I suppose you know it worked if you see the topic.)

Hi Jack,

Yes, evidently, the topic was created!

I’ve seen the same issue. tl;dr: one message is threaded below another only if it is its child. So two messages where neither is a child of the other, even with the same subject, are shown as siblings. When they are both at the top level, you see that splintering of the thread.

Background: that Merge threads with the same subject option is implemented in the spirit of JWZ’s algorithm, though possibly not to the letter. One feature of that algorithm is that, when parent-child relationships cannot be determined by the messages’ msg-ids and references, they are decided by the level of Re: quoting in the subjects. So if they are the same level, it is not possible to decide which is the parent and which the child. In that case, they are declared to be siblings, and displayed at the same level. If that happens to be the top level, they’re shown as separate heads of their own threads.

The basic issue is that Balsa organizes messages into tree-structured threads, rather than into less structured topics.

I vaguely recall that earlier discussion, and I believe I actually traded some email with JWZ himself.

Wouldn’t it be reasonable in such cases to make the older message the parent? Maybe even with a different configuration check box to avoid surprises. I don’t think it would be used/needed often, but it would certainly save me some extraneous sorting and filtering. Maybe it only needs to happen at the top level, as making them siblings within an existing thread would be fine for me. My case is when they are at top level but far apart in time.