Re: [Evolution] "Include threads:" setting for Search Folders?

[Milan Crha <mcrha redhat com>]

On Thu, 2017-11-02 at 08:31 -0700, Paul Rozdeba wrote:
> If I choose "All local and active remote folders" as my sources, then
> the folder shows threads where I am the sender, along with with all
> related messages from every IMAP folder *except* the Inbox! If I
> choose to only include <account>: INBOX and <account>: [Gmail]/Sent
> Mail, then I get a similar result where all I see are messages in my
> Sent folder. In other words, the search folder seems to ignore the
> inbox as a source.

        Hi,
my test case was slightly simpler. I created two folders under On This
Computer/... account, then I took one thread and copied first half of
the thread to one of those folders and the other half to the other
folder. Then I created a search folder which reads:

   Find items which match: [ all the following conditions ]
   [ Sender ] [ contains ] [ name    ]
   [ Specific folders ]
   [ On This Computer : Inbox/folder-1     [ ] include subfolders ]
   [ On This Computer : Inbox/folder-2     [ ] include subfolders ]

Then I played with the Include threads option. Having it None, I see
only messages from that 'name' and from both folders. When using [ All
related ], it reconstructs the complete thread as a merge of messages
from both folders.

But, I see it's not the same as using Inbox and Sent folders. The
difference is that I used a thread which is from a mailing list and I
split it in a way that the sender it matches was in both folders.
Trying with Inbox and Sent folder for the simplest thread:

   Message (in Inbox)
     Re: Message (in Sent)

The Sender I use is a sender in the Inbox, but a recipient in the Sent.
The problem seems to be that the Sent folder doesn't have a hit on the
Sender thus the "Include threads" option skips the Sent folder from
consideration, or something like that (I'm still lazy to read the
code). That kind of makes sense, because the search folder tries to
limit messages to merge as much as possible, instead of creating a
really big virtual folder and run the filtering on top of it. This
approach works, as long as threads are not involved.

Your better option would be to wait for a build-in conversation
view [1] or workaround it by a simple merge of the messages in those
two folders (use Match all condition with Include threads: None).
You can reference search folders in search folders as well, thus then
you can create the filter by Sender search folder with All related
threads referencing the merge of Inbox & Sent search folder and it'll
work. It doesn't work for Message Location, because the message
location is the search folder.

Okay, all these things are getting quite complicated, and the threads-
thing even more, not talking about performance hit when it's comparing
for the thread-related messages. Thus, from my point of view, the merge
of the Sent & Inbox (or other folder) is a good workaround.
        Bye,
        Milan

[1] Something like this one:
    https://bugzilla.gnome.org/show_bug.cgi?id=258233
    and yes, it's ancient. Adding it to evolution is not that easy,
    as it might look like. At least not efficiently enough.