[OSM-dev] [OSM-talk] Trouble in Rangoon

[bvh]

On Thu, Feb 28, 2008 at 02:44:06PM +0100, Frederik Ramm wrote:
> The only thing I'd ask of editors is to support "create_changeset"  
> and then use the ID returned on subsequent edits. This, I believe, is  
> a small price to pay for the grouping advantages we would get.  
> Automatically creating one changeset for every single change would be  
> an option for a changeover time but not really desirable.

How would it deal with conflicts? Ie with the following timeline of calls

node a is initially at state a0
- user X create_changeset 1
- user X change node a to state a1
- user Y create_changeset 2
- user Y change node a to state a2
- user Y close_changeset 2
- user X change node a to state a3
- user X close_changeset 1

Now revert changeset 2.
To what state should node a revert? a0, a1, or a3?
And this is even a 'simple' case. But imagine much more complex scenarios
where user Y is actually changing a turn restriction while user
X is changing the direction of one of the ways that is part of said
turn restriction.

cu bart