root cause of split threads?

[timotheecour]

I constantly see threads being split for no reason, but couldn't find an issue to track/investigate this. Recent example:

• thread start: option -ignore_pure for temporary debugging (or how to wrap an unpure function inside a pure one)? https://forum.dlang.org/post/mailman.3227.1518060629.9493.digitalmars-d@puremagic.com

• thread reply Re: option -ignore_pure for temporary debugging (or how to wrap an unpure function inside a pure one)? https://forum.dlang.org/post/mailman.3228.1518060762.9493.digitalmars-d@puremagic.com

EDIT: from @CyberShadow

This is an old issue caused by Mailman rewriting message-IDs. It is a long-standing anti-feature that causes breakages in software like this. On the forum, it happens when a mailing-list user replies to another mailing-list user.

EDIT: https://gitlab.com/mailman/mailman/issues/24 NNTP gatewaying trashes Message-IDs seems to have some workarounds proposed

[CyberShadow]

I answered this 10 minutes ago in your other issue:

This is an old issue caused by Mailman rewriting message-IDs. It is a long-standing anti-feature that causes breakages in software like this. On the forum, it happens when a mailing-list user replies to another mailing-list user.

https://github.com/CyberShadow/DFeed/issues/98#issuecomment-364363321

[timotheecour]

• is there any workaround or it's really hard to fix? couldn't we merge issues by title which only differ by leading Re:* ?

• who can I (as a user) not cause it? reply only to mailing list but not "reply all" ?

[CyberShadow]

is there any workaround or it's really hard to fix?

A workaround is possible:

• Subscribe to both NNTP and mailing list
• Keep track of two message-IDs per message
• When a message is received on both, try to match up their message IDs

couldn't we merge issues by title which only differ by leading Re:* ?

That would be error-prone, there are many threads with the same title.

who can I (as a user) not cause it?

Don't use the mailing lists to post - use forum.dlang.org or NNTP instead.

[timotheecour]

I found this: https://www.mail-archive.com/mailman-users@python.org/msg63313.html

unfortunatily mailman is rewriting the Message-Id of
> > the injected emails.
> 
> 
> What Mailman version is this? This should not happen unless General
> Options -> anonymous_list is Yes or the new in 2.1.16 General Options ->
> from_is_list setting is Wrap Message.
> 

Hei Presto,

Changing the setting of anonymous_list to no has resulted in the correct
Message-Id.

Thanks for the fast and correct response.

[quickfur]

@timotheecour Sounds like that might be relevant for our little problem here. Can we at least try this out to see if it works? ping @CyberShadow

[CyberShadow]

Well, we would need to ask Brad to change the setting.

Does anonymous_list have any side effects other than disabling the mangling of message IDs?

[quickfur]

Honestly, I have no idea. But perhaps @brad-anderson would know?

[CyberShadow]

That's the wrong Brad, you want @braddr :)

[quickfur]

Haha, thanks!