setPrecision crashes when collapsing linearring

[caspervdw]

The following command (through pygeos) results in a segmentation fault:

pygeos.set_precision(pygeos.Geometry("LINEARRING (0 0, 0.1 0, 0.1 0.1, 0 0.1, 0 0)"), 1.0, flags="make_valid")

It is just the linearrings, linestrings and polygons with the same coordinates give correct results (empty geometries).

[caspervdw]

The same geometry with KEEP_COLLAPSED gives the surprising result LINESTRING (0 0, 0 0, 0 0)

[Paul Ramsey <pramsey@…>]

In 5e44ec3/git:

Check for empty Sequence when collapsing linear ring. References #1135

[Paul Ramsey <pramsey@…>]

In 14f0a69/git:

Check for empty Sequence when collapsing linear ring. References #1135

[Paul Ramsey <pramsey@…>]

In b14c228/git:

Fix crasher reducing LinearRing precision, references #1135

[pramsey]

Yep, the algorithm feels that a valid linestring is "better" than a collapsed zero-area (self-intersecting) ring. Angels dance.

[caspervdw]

Thanks for the fix!