[makevalid] [constrainted triangulation] panic in (*QuadEdge).Sym

[ear7h]

Testing the new simplification function, I am running into a nil pointer dereference.

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x467a656]

goroutine 407 [running]:
github.com/go-spatial/tegola/atlas.Map.Encode.func1.1.1(0xc0002e1aa0, 0xc000c67e00, 0xc0070f7358)
	/Users/julio/lib/go/src/github.com/go-spatial/tegola/atlas/map.go:215 +0x505
panic(0x49c0580, 0x527c920)
	/usr/local/go/src/runtime/panic.go:679 +0x1b2
github.com/go-spatial/geom/planar/triangulate/quadedge.(*QuadEdge).Sym(...)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/triangulate/quadedge/quadedge.go:251
github.com/go-spatial/geom/planar/triangulate/constraineddelaunay.(*Triangulator).deleteEdge(0xc0070f6f58, 0xc0009644e0, 0x41716c4ca9fb7e18, 0x415ffcf349193de5)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/triangulate/constraineddelaunay/triangulator.go:162 +0xa6
github.com/go-spatial/geom/planar/triangulate/constraineddelaunay.(*Triangulator).insertEdgeCDT(0xc0070f6f58, 0xc0070f6a88, 0x0, 0x0, 0x0, 0x0)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/triangulate/constraineddelaunay/triangulator.go:757 +0x1678
github.com/go-spatial/geom/planar/triangulate/constraineddelaunay.(*Triangulator).insertConstraints(0xc0070f6f58, 0x49d6e80, 0xc0014c3320, 0x0, 0x0, 0x0, 0x42d7c700ad4cb1c5)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/triangulate/constraineddelaunay/triangulator.go:460 +0x5a8
github.com/go-spatial/geom/planar/triangulate/constraineddelaunay.(*Triangulator).InsertGeometries(0xc0070f6f58, 0xc0070f6f48, 0x1, 0x1, 0x0, 0x0, 0x0, 0xc0070f6ee0, 0x466d202)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/triangulate/constraineddelaunay/triangulator.go:373 +0x13b
github.com/go-spatial/geom/planar/makevalid.TriangulateGeometry(0x4c38980, 0xc0008cd350, 0x49d6e80, 0xc0014c3320, 0x54, 0x5c, 0x56, 0xc0070f7010, 0x409f999)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/makevalid/triangulate.go:19 +0xb3
github.com/go-spatial/geom/planar/makevalid.InsideTrianglesForGeometry(0x4c38980, 0xc0008cd350, 0x49d6e80, 0xc0014c3320, 0x4c31c00, 0xc00411fd20, 0x0, 0x0, 0x0, 0xc000099800, ...)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/makevalid/triangulate.go:57 +0x6a
github.com/go-spatial/geom/planar/makevalid.(*Makevalid).makevalidPolygon(0xc0070f7388, 0x4c38980, 0xc0008cd350, 0xc000798020, 0xc0014c3320, 0x1, 0x0, 0xc0070f7218)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/makevalid/makevalid.go:194 +0x11c
github.com/go-spatial/geom/planar/makevalid.(*Makevalid).Makevalid(0xc0070f7388, 0x4c38980, 0xc0008cd350, 0x49cd360, 0xc00683a2a0, 0xc000798020, 0x0, 0xc00683a2a0, 0x0, 0x0, ...)
	/Users/julio/lib/go/src/github.com/go-spatial/geom/planar/makevalid/makevalid.go:235 +0x57c
github.com/go-spatial/tegola/atlas.Map.Encode.func1.1(0xc0015a0000, 0x0, 0x0)
	/Users/julio/lib/go/src/github.com/go-spatial/tegola/atlas/map.go:254 +0x384
github.com/go-spatial/tegola/provider/postgis.Provider.TileFeatures(0xc0000d1570, 0x9, 0x1538, 0xc0000d15a0, 0xd, 0xc0000d15d0, 0x6, 0x0, 0x0, 0x0, ...)
	/Users/julio/lib/go/src/github.com/go-spatial/tegola/provider/postgis/postgis.go:601 +0xa41
github.com/go-spatial/tegola/atlas.Map.Encode.func1(0xc000cbe450, 0xc000c67e00, 0xc000255d90, 0x2, 0xc00027ede0, 0x10, 0x520d660, 0xc053119efffcb851, 0x404393a5a4fa85e7, 0x4014000000000000, ...)
	/Users/julio/lib/go/src/github.com/go-spatial/tegola/atlas/map.go:166 +0x272
created by github.com/go-spatial/tegola/atlas.Map.Encode
	/Users/julio/lib/go/src/github.com/go-spatial/tegola/atlas/map.go:154 +0x208

[gdey]

Do you have the geo that is getting simplified that is causing that panic? It would be interesting to see what is being passed into the make valid.

Looks the issue is happening after edge delation to add a constraint.

[ear7h]

@gdey yep, just took me a bit to upload

https://gist.github.com/ear7h/b231f1bf4ff4b3c74555a0c2fb30208d

[gdey]

We moved away from this library.