shp import: Shared borders represented as duplicated ways.

[StefanB]

When importing .shp file into JOSM happens that the result has some shared borders that are represented as duplicated wasy

JOSM validator then reports;

warning: Ways with same position (much too many), when duplicated ways only differ in tags, eg a multipolygon inner border (no tag, just a member of multipolygon relation) overlaps with the same simple polygon (with a simple tag) (example: a meadow within a forest multipolygon) yellow in the picture below:
image
fixable by reusing the simple tagged way also as a member of multipolygon relation

error: Duplicated ways (regular occurance) when both overlapping ways have the same tags, or no tags if they are both members of different relations. (example: outer/exclave meadow within a forest multipolygon or multi-level-multipolygons) red in the picture below:
image
fixable by reusing same way (the only one) in both relations

warning: Self-intersecting way (some) when it is drawn as such in .shp, probably unrelated
image
fixable by reordering nodes within way?

See ​https://github.com/pnorman/ogr2osm/issues/28 for graphic examples

[Don-vip]

In 7721/josm:

see #10743 - code refactoring to allow reuse of duplicated ways algorithm in plugins

[Don-vip]

Fixed in [o30796:30797].

[StefanB]

Thanks!

I tested the latest build 7722 and the validation is not reporting neither error (Duplicated ways) nor warning (Ways with same position) anymore. Everything looks fine.

I wwould just like to confirm whether it was legit to adjust the validation algorithm instead of import algorithm, meaning that the data is ok as it is?

[StefanB]

I wwould just like to confirm whether it was legit to adjust the validation algorithm instead of import algorithm, meaning that the data is ok as it is?

I checked the structure in the .osm xml file, and everything seems to be ok. Ways are indeed not duplicated, but unique and nicely referenced from relations.

Thanks again!