(Multi)polygon fixing effort

[openstreetmap-trac]

Reporter: Jochen Topf
[Submitted to the original trac issue database at 1.14pm, Friday, 17th March 2017]

There is a major effort going on to fix broken (multi)polygons in OSM and also to finally get rid of old-style multipolygon relations. This will hopefully lead to simpler and more efficient software. There is no immediate need for you to change anything in Potlatch, but I would expect there to be opportunities to simplify your code and generally make life easier for you once this effort is successful.

I wanted to make you aware of the effort and get you involved in the discussions. We'd also appreciate it if you can support this effort in any way. Find all the details at http://area.jochentopf.com/. We are coordinating with other software project through our issue osmlab/fixing-polygons-in-osm#23.

[openstreetmap-trac]

Author: Richard
[Added to the original trac issue at 2.20pm, Friday, 17th March 2017]

Yeees. :|

The main issue is presumably that P2's multipolygon UI creates so-called "old-style" multipolygons (i.e. tags on the outer way) rather than "new-style" (tags on the relation).

I had been waiting for the API to get a proper area datatype instead, as IMO multipolygons (of any stripe) are a horrible hack - putting geometry information in a structure designed for metadata. But that doesn't look like it's happening any time soon (read: in the 21st century).

The challenge here is going to be getting the tagging UI to look at an object which is essentially not the currently selected one. This will require (presumably significant) rewiring of the tagging internals, as well as a new UI element to allow the user to switch between editing the tags on the relation and the outer way. (Even if the relation becomes the default, we should still allow editing the tags on the way; and what of ways that form parts of multiple multipolygons?)

See thread: https://lists.openstreetmap.org/pipermail/dev/2011-October/023555.html

---

Dusting off the relevant bits of the source, it looks like setEntity in TagViewer.mxml is going to be where most of this happens.

[openstreetmap-trac]

Author: Richard
[Added to the original trac issue at 12.12pm, Friday, 24th March 2017]

Fixed in systemed/potlatch2@d53e6c5