[PostGIS] #6028: Mis-shapen Empty Polygon Crashes Backend

[PostGIS]

#6028: Mis-shapen Empty Polygon Crashes Backend
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  Reporter:  pramsey  |      Owner:  pramsey
      Type:  defect   |     Status:  new
  Priority:  blocker  |  Milestone:
 Component:  postgis  |    Version:  3.2.x
Resolution:           |   Keywords:
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Description changed by pramsey:

Old description:

> From the mailing list
> {{{
> drop table if exists fault;
> create table fault (fid integer, geom geometry(Polygon,5015));
> CREATE INDEX fault_geom_index ON fault USING GIST (geom);
> INSERT INTO fault (fid, geom) VALUES (1,
> '0103000020971300000100000000000000'::GEOMETRY);
> }}}
> The polygon in the WKB is a polygon with one ring, which has zero points.
> This is legal WKB, but not really distinct from an empty polygon
> represented with zero rings, from a spatial logic point of view. It still
> covers no space and is a polygon.
>
> When parsing this input WKB, it makes sense to just convert the input
> into a standard empty polygon.

New description:

 From the [https://lists.osgeo.org/pipermail/postgis-
 users/2025-December/046990.html mailing list]
 {{{
 drop table if exists fault;
 create table fault (fid integer, geom geometry(Polygon,5015));
 CREATE INDEX fault_geom_index ON fault USING GIST (geom);
 INSERT INTO fault (fid, geom) VALUES (1,
 '0103000020971300000100000000000000'::GEOMETRY);
 }}}
 The polygon in the WKB is a polygon with one ring, which has zero points.
 This is legal WKB, but not really distinct from an empty polygon
 represented with zero rings, from a spatial logic point of view. It still
 covers no space and is a polygon.

 When parsing this input WKB, it makes sense to just convert the input into
 a standard empty polygon.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/6028#comment:3>
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