Handling unmergeable files -- a call to arms

[Stephen J. Turnbull]

David Ingamells writes:

 > How will the developer working on that computer (e.g. while riding in a 
 > bus) check/set a lock if he wants to edit such an unmergeable file?

It doesn't take a physicist to know he can't.  Developers who want to
work on unmergeable files while disconnected have two choices:

1.  Grab the lock while connected, then go (and risk taking a
    well-deserved wet-noodle whipping when they reconnect), or

2.  Create a new head (and risk doing the merge by eye when their
    edits conflict with somebody else's).

Well, three, I guess.  There's also

3.  Grit your teeth, let the deadline slip, and while you're on the
    bus invent and implement a merge algorithm for the heretofore
    unmergeable file. :-)