Handling unmergeable files -- a call to arms

[Ewan Milne]

Russel:

> Paul,
>
> On Fri, 2009-05-29 at 11:19 -0700, Paul Schauble wrote:
>> I don't think 4 works. There may be hundreds of Bazaar repositories that
>> contain the file, many of which are currently unreachable by network.
>> For a lock to work it would have to lock every single one of these
>> repositories. And you can't do it.
>
> Agreed.
>
> The original problem is not to try and create a generalized global
> operation -- as people have pointed out this is not possible in general,
> and is counter to the whole DVCS thing.

Also agreed: it is clear that this is only feasible when using a
centralized workflow.

>> I think the best that can be done in this case is to keep all of the
>> conflicting versions of the file in the repositories as they are updated
>> and to note the conflict as requiring human intervention. This doesn't
>> necessarily leave you merging by eye. A lot of work processors and
>> graphics programs have merge features. But Bazaar can't do it.
>
> If using DVCS then yes, human merging is required.  FrameMaker and
> OpenOffice.org have change tracking, but as far as I am aware they don't
> have actual merge functions.
>
> However, the context of the original issue is a centralized workflow.
> There is one, and only one repository, any other branch or clone is a
> cache not a peer.  So the problem is to lock the master copy of a file
> so it is writeable only by the owner of the lock.  There is no intention
> to try and generalize this in any way.
>
> The idea Martin put forward of using a plugin are the way forward here,
> and I had been thinking along the same lines as he expressed of managing
> a lock list.  Given the context and the aim, I think there is a very
> viable solution.  All that is required is to find enough person hours to
> get the design in a state where a prototype can be built.

A plugin-based solution seems like a good approach in this context: as
we are talking about a centralized workflow, it is reasonable to
require that all users have a plugin installed.