Comment 12 for bug 109730

I don't think the locking is particularly important -- what would be super duper useful is a way to indicate who is currently working on what file - this is especially useful for when working with binary files that won't merge smoothly.
This would mean that a user would have a means of indicating that they are currently making changes to the file and other users can check to see who is currently working on the file and contact them if they both want to be doing the same thing to the same file at the same time. IDE integration tools etc could probably do this automatically