disallow changes to tickets if it was modified since user got it

[mrovner@…]

Like svn prohibits checking in outdated version of file, Trac should not allow modifying a ticket if it was changed by another user in the meantime.

[ph@…]

If both users change properties, even if they don't change the same properties (because they can be somewhat interdependent, ex: what may be a high priority task when assigned to Alice is not if assigned to Bob), the second user to submit their changes should get a 'rejected' screen like the Wiki gives.

Comments, even if they went along with rejected changes, should always be accepted. There's very little potential for harm in this.

[ludde]

Disable concurrent edits. Comments are still allowed.

[Mark Rowe]

I disagree. If a user makes changes to multiple properties in one go, including a comment, then they should be treated as a unit. If the ticket has been modified since the user received the form, then all the changes should be rejected. To have the comment added anyway would be highly confusing IMO.

[Christian Boos]

That's how ludde implemented it: if any field has been changed, the comment is rejected.

[Jonas Borgström]

Comitted a simpler solution in [1898] that rejects changes to tickets to tickets that have been modified since the user started editing. Comments are treated no different than any other property.