s2_rebuild transforms `POLYGON FULL` into an empty geometrycollection
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- Dominant language
- C++
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- 81
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- Avg merge
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Description
I'm (finally) implementing support for POLYGON FULL in sf, and ran into s2_rebuild converting an s2 full polygon to a GEOMETRYCOLLECTION EMPTY. I don't think it should! I'll work around it in sf, but it would be nice if it wasn't touched in s2_rebuild: In a debug session in sf::st_make_valid():
Browse[1]> s2
<geodesic s2_geography[2] with CRS=OGC:CRS84>
[1] POLYGON ((0 -90, 0 -90)) POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0...
Browse[1]>
debug: s2 = s2::s2_rebuild(s2, s2_options)
Browse[1]>
debug: st_as_sfc(s2, crs = crs)
Browse[1]> s2
<geodesic s2_geography[2] with CRS=OGC:CRS84>
[1] GEOMETRYCOLLECTION EMPTY POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0...
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- Read the whole issue, then the project's contributing guide.
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Research direction
Start with s2::s2_rebuild as called from sf::st_make_valid(), and reproduce the POLYGON FULL example shown in the issue. Trace how the full polygon is converted during rebuilding, then verify that the result remains a full polygon rather than becoming GEOMETRYCOLLECTION EMPTY.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- cpp, r
- Domain
- computer-graphics
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 48/100