* Move content on moving topics between streams to a dedicated
article. We advertise it as "move content" to hint that one can move
messages or split topics, and link to it.
* This deletes change-the-topic-of-a-message, because the same content
is already covered in rename-a-topic.
* This commit mostly just moves content between articles. Most of that
content was redundant with the first few paragraphs of the surviving
"rename a topic" article. The former "This is useful for" se ntence
was adapted to the remaining article.
* This commit also adds a redirect for the removed article, and
updates related links.
Fixes#16284.
Most of the work for this was done when we implemented correct
behavior for guest users, since they treat public streams like private
streams anyway.
The general method involves moving the messages to the new stream with
special care of UserMessage.
We delete UserMessages for subs who are losing access to the message.
For private streams with protected history, we also create UserMessage
elements for users who are not present in the old stream, since that's
important for those users to access the moved messages.
* This feature is currently only visible to admins.
* Locally echoed messages are also updated.
* Add UI for editing stream if user is admin.
* Show propagate mode selector if either stream or topic changed.
This completes the implementation of support for moving a topic to
another stream by adding a basic UI for it.
Fixes#6427, which was previously the most-upvoted issue request in
Zulip.
There are likely to be a bunch of follow-up UI improvements on top of
this change to fully flesh out the feature.
Damian Parrino
Tim Abbott
sahil839
Aman Agrawal
Aman Agrawal
Tim Abbott
Rishi Gupta