[PostGIS] #5632: After creating the index of GIST, ST_Equals gives the incorrect answer.

[PostGIS]

#5632: After creating the index of GIST, ST_Equals gives the incorrect answer.
---------------------+---------------------------
 Reporter:  Wenjing  |      Owner:  pramsey
     Type:  defect   |     Status:  new
 Priority:  medium   |  Milestone:  PostGIS 3.4.2
Component:  postgis  |    Version:  3.4.x
 Keywords:           |
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 Consider the following statements:

 {{{

 DROP TABLE IF EXISTS t;
 CREATE TABLE t (id int, geom geometry);
 INSERT INTO t (id, geom) VALUES (1,ST_GeomFromText('GEOMETRYCOLLECTION
 EMPTY'));
 INSERT INTO t (id, geom) VALUES (2,NULL);
 INSERT INTO t (id, geom) VALUES (3,ST_GeomFromText('GEOMETRYCOLLECTION
 EMPTY'));
 INSERT INTO t (id, geom) VALUES (4,NULL);
 SELECT COUNT(*)         FROM t As a1          RIGHT OUTER JOIN t As a2 ON
 ST_Equals(a1.geom, a2.geom)          WHERE   a1.id <> a2.id;
 -- result{2}
 CREATE INDEX idx ON t USING GIST (geom);
 SELECT COUNT(*)         FROM t As a1          RIGHT OUTER JOIN t As a2 ON
 ST_Equals(a1.geom, a2.geom)          WHERE   a1.id <> a2.id;
 -- actual{0}; expected{2}

 }}}

 After creating the index of GIST, ST_Equals gives the incorrect answer.
 The correct equal pairs could be (1,3), (3,1), while PostGIS gives 0 rows
 using COUNT(*).

 The version is the newest on GitHub:

 {{{
 POSTGIS="3.5.0dev 3.4.0rc1-818-g6c2e935b6" [EXTENSION] PGSQL="170"
 GEOS="3.13.0dev-CAPI-1.18.0" PROJ="8.2.1
 NETWORK_ENABLED=OFF URL_ENDPOINT=https://cdn.proj.org/
 USER_WRITABLE_DIRECTORY=/tmp/proj DATABASE_PATH=/usr/
 share/proj/proj.db" LIBXML="2.9.13"
 }}}
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5632>
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