[PostGIS] #5726: Cases where ST_Overlaps(ST_Difference(a, b), b) = TRUE

[PostGIS]

#5726: Cases where ST_Overlaps(ST_Difference(a,b),b) = TRUE
-------------------------+---------------------------
  Reporter:  dannytoone  |      Owner:  pramsey
      Type:  defect      |     Status:  closed
  Priority:  medium      |  Milestone:  PostGIS 3.4.3
 Component:  postgis     |    Version:  3.4.x
Resolution:  wontfix     |   Keywords:
-------------------------+---------------------------
Changes (by pramsey):

 * status:  new => closed
 * resolution:   => wontfix


Old description:

> {{{
> POSTGIS="3.4.1 ca035b9" [EXTENSION] PGSQL="160" GEOS="3.12.1-CAPI-1.18.1"
> PROJ="9.2.1 NETWORK_ENABLED=OFF URL_ENDPOINT=https://cdn.proj.org
> USER_WRITABLE_DIRECTORY=/Users/DToone2/Library/Application Support/proj
> DATABASE_PATH=/Applications/Postgres.app/Contents/Versions/16/share/proj/proj.db"
> LIBXML="2.11.7" LIBJSON="0.17" LIBPROTOBUF="1.4.1" WAGYU="0.5.0
> (Internal)"
> }}}
>

> I'm having a tough time thinking through the relational geometry of this,
> and I can't help but think this is a bug. If b is cut out from a, then
> the result should intersect with b along the shared boundary, but it
> shouldn't overlap. A resulting overlap would indicate that the
> ST_Difference was not complete. I've recently found several cases where
> `ST_Overlaps(ST_Difference(a,b),b) = TRUE`, and I thought I'd file a bug
> report to make sure.

New description:

 {{{
 POSTGIS="3.4.1 ca035b9" [EXTENSION] PGSQL="160" GEOS="3.12.1-CAPI-1.18.1"
 PROJ="9.2.1 NETWORK_ENABLED=OFF URL_ENDPOINT=https://cdn.proj.org
 USER_WRITABLE_DIRECTORY=/Users/DToone2/Library/Application Support/proj
 DATABASE_PATH=/Applications/Postgres.app/Contents/Versions/16/share/proj/proj.db"
 LIBXML="2.11.7" LIBJSON="0.17" LIBPROTOBUF="1.4.1" WAGYU="0.5.0
 (Internal)"
 }}}


 I'm having a tough time thinking through the relational geometry of this,
 and I can't help but think this is a bug. If b is cut out from a, then the
 result should intersect with b along the shared boundary, but it shouldn't
 overlap. A resulting overlap would indicate that the ST_Difference was not
 complete. I've recently found several cases where
 `ST_Overlaps(ST_Difference(a,b),b) = TRUE`, and I thought I'd file a bug
 report to make sure.

--
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Ticket URL: <https://trac.osgeo.org/postgis/ticket/5726#comment:2>
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