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Changes between Version 1 and Version 2 of Ticket #2568

v1	v2
3	3	This is an easy mistake to make and could cause data loss. Alice has lost her write cap to her DMD, and there is no way to get it back (only a read cap to that directory is linked from the collective directory). Also, Alice's magic folder db will be inconsistent with the DMD that she is now using.
4	4
5		The above problem is easy to fix by making it an error for a client to join a magic folder when it has one already configured. (Perhaps a `tahoe magic-~~client~~ leave` command could be added; this would disable magic folder and also delete the magic folder db.)
	5	The above problem is easy to fix by making it an error for a client to join a magic folder when it has one already configured. (Perhaps a `tahoe magic-folder leave` command could be added; this would disable magic folder and also delete the magic folder db.)
6	6
7	7	A related but trickier problem is that if the invite code is used twice, then two clients will be writing to the same DMD. There's no way to enforce that an invite code is single-use, because `join` is a strictly local operation that has no side effects on the collective directory. This has some advantages --if you lose state but retain the invite code then you can re-join-- but is also a little error-prone.