Topic splitting

[julianlam]

Allow an admin to split topics into two separate topics.

• Option in thread tools dropdown
• Client-side overlay allows admin to select which posts to migrate to a new topic
• New topic created, and posts moved over (may necessitate creation of a movePidToTid method)

[psychobunny]

Need mechanism to decide topic title, as well as potentially including instructions on what to do. Mock up for post selector overlay:

Edit: Maybe a position: fixed floating menu with "Create Topic / Cancel" buttons and an input box to enter new topic title

[cnvo]

This would be a nice feature to have. 👍