On 27 Apr 2009, at 20:44, Frederik Ramm wrote: > Hi, > > (CC'ing Chris Browet because I'd like to know if Merkaartor has come > up > with a solution for this problem that we could use!) > > Shaun pointed out the following problem with conflict resolution > (which is not new, it was present in pre-0.6 times too): > >> Nick downloads an area. >> Steve downloads the same area. >> Nick deletes node 23 and uploads. >> Steve changes a tag on node 23. >> Steve does an update, and does not get an update about the fact that >> Nick deleted node 23. >> When Steve uploads all he gets is a Gone HTTP status. > > I see several issues here: > > Firstly, Steve should not get "Gone" in the last step; he should get > whatever the usual version mismatch error code is - after all he tries > to upload his change based on an old version of node 23. This is > potentially an API bug.
It could be that the file that I have has some other problem which is causing the gone. I do have an improvement to the error message, when a node/way/relation has been deleted, which hasn't been deployed yet. Hopefully that will help to debug what is going on. http://trac.openstreetmap.org/changeset/14783 > > But, more importantly, how could we achieve that Steve's session gets > wind of the fact that Nick has deleted the node? > > Idea 1: Implement a kind of "list all objects deleted from this area > within the last X minutes" API call which JOSM could use. This would > slow down the download and increase API load but probably be a stable > way to deal with it. > > Idea 2: Before re-downloading an area, let JOSM mark all objects that > came from the API on the last download as "possibly deleted". On > merging > the newly downloaded dataset with the existing data, reset that flag > for > every object retrieved from the API. The remaining objects flagged > "possibly deleted" have been deleted on the server and should either > be > silently removed, or if they have local modifications, a conflict > dialog > needs to be shown. > It could be that someone has moved the node outside the area, so the best option would be to do a read on that node/way/relation as suggested by Avar (no don't screenscrape, use the HTTP status code and any xml returned). Shaun > Further ideas, comments? > > Bye > Frederik > > -- > Frederik Ramm ## eMail [email protected] ## N49°00'09" > E008°23'33" > > _______________________________________________ > josm-dev mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/josm-dev _______________________________________________ josm-dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/josm-dev
