Improve email threading
This is a follow-up to !112 : it improves email threading, without changing the receiver of the emails.
* Subject of answers to an existing thread begins with `Re: ` (required by Mail.app)
* Send a 'In-Reply-To' header along the 'References' header
* send a ‘In-Reply-To’ header along the ‘References’ header
* subject of answers to an existing thread begins with ‘Re: ’
This fixes threading with at least Mail.app and Airmail.
This fixes email threading in Mail.app, that doesn't like when a thread
doesn't have stable recipients.
For instance, here is a possible sender-recipient combinations before:
From: A
To: Me
New issue
From: B
To: Me
Reply on new issue
From: A
To: Me
Another reply
Mail.app doesn't see B as a participant to the original email thread,
and decides to break the thread: it will group all messages from A
together, and separately all messages from B.
This commit makes the thread look like this:
From: A
To: gitlab/project
Cc: Me
New issue
From: B
To: gitlab/project
Cc: Me
Reply on new issue
From: A
To: gitlab/project
Cc: Me
Another reply
Mail.app sees a common recipient, and group the thread correctly.
The 'author_id_of_changes' attribute is not persisted in the database.
As we retrieve the merge request from the DB just before sending the
email, this attribute was always nil.
Also there was no tests for the merge notification code - tests have
been added.
Fix#6605
Every email has a different way of showing a link to the discussion on
the website. We don't need this anymore, as we now have a standard
"View in GitLab" link in the footer of every email.
When an email notification concerns a specific object (issue, note,
merge request, etc.), add a link to the footer of the email that opens
the item's page in a web browser.
Rationale:
* The link is predictable: always the same text, always at the same
location, like any reliable tool.
* It allows to remove the inline-title in many emails, and leave only
the actual content of the message.
This changes the email "From" field from "gitlab@example.com" to either:
* "John Doe <gitlab@example.com>" if the author of the action is known,
* "GitLab <gitlab@example.com>" otherwise.
Rationale: this allow mails to appear as if they were sent by the
author. It appears in the mailbox more like a real discussion between
the sender and the receiver ("John sent: we should refactor this") and
less like a robot notifying about something.
This changes the email subjects for issues and merge request
notifications from:
Team / Project | Note for issue #1234
to:
Team / Project | Saving issue doesn't work sometimes (#1234)
Rationale:
* Scan the subject of the email notification more easily when catching
up with a lot of notifications. Instead of having to open the email to
get the title of the issue or merge request, one can simply read the
subject of the email.
* Group messages by subject: email clients will group emails in threads
if they have the same subject.
Douwe Maan
Dmitriy Zaporozhets
Jakub Jirutka
Vinnie Okada
Steven Burgart
Jacob Vosmaer
Pierre de La Morinerie
Marin Jankovski
Alex Elman
Philip Blatter
Drew Blessing
Jonathan A. Sternberg