ST_3DDistance seems not to work for LINESTRINGs in specified situation.

[Wenjing]

Consider the following statement

SELECT ST_3DDistance(b1, b2)  
FROM ST_GeomFromText('LINESTRING Z (0 0 0, 1 0 0)') As b1,
ST_GeomFromText('LINESTRING Z (0 0 0, 1 1 1)') As b2;
--  st_3ddistance 
---------------
--              
-- (1 row)

The ST_3DDistance function is expected to give the result but it doesn't.

The version:

 POSTGIS="3.5.0dev 3.4.0rc1-705-g5c3ec8392" [EXTENSION] PGSQL="170" GEOS="3.13.0dev-CAPI-1.18.0" PROJ="8.2.1 NETWORK_ENABLED=OFF URL_ENDPOINT=https://c
dn.proj.org USER_WRITABLE_DIRECTORY=/tmp/proj DATABASE_PATH=/usr/share/proj/proj.db" LIBXML="2.9.13"
(1 row)

[robe]

I confirm this is not working and gives a NULL as you say. Very strange. Tested on 3.4.0 and 3.5.0

[Wenjing]

Paul, did you have a chance to look at this one? It is very strange. @pramsey

[pramsey]

I also see NULL. So.

[Paul Ramsey <pramsey@…>]

In bccab952/git:

ST_3DDistance on segments with identical start, references #5589

[Paul Ramsey <pramsey@…>]

In 94e5b95d/git:

ST_3DDistance error for shared first point, references #5589

[Paul Ramsey <pramsey@…>]

In 5c276bc/git:

ST_3DDistance error for shared first point, references #5589

[Paul Ramsey <pramsey@…>]

In 98d112f/git:

ST_3DDistance error for shared first point, references #5589

[Paul Ramsey <pramsey@…>]

In 4425662/git:

ST_3DDistance error for shared first point, references #5589