St_AddPoint always adds the new point in position 0 for each position provided apart for -1 or leaving it out

[pizzuga]

In my Debian 9.12 (both postgres 11 and 12 are running on the same machine and both affected by the bug) with postgis_full_version as:

POSTGIS="3.0.1 ec2a9aa" [EXTENSION] PGSQL="120" GEOS="3.7.1-CAPI-1.11.1 27a5e771" PROJ="Rel. 4.9.3, 15 August 2016" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.2.1" WAGYU="0.4.3 (Internal)"

and

POSTGIS="2.5.4" [EXTENSION] PGSQL="110" GEOS="3.7.1-CAPI-1.11.1 27a5e771" PROJ="Rel. 4.9.3, 15 August 2016" GDAL="GDAL 2.1.2, released 2016/10/24" LIBXML="2.9.4" LIBJSON="0.12.1" LIBPROTOBUF="1.2.1" (core procs from "2.5.2 r17328" need upgrade) RASTER (raster procs from "2.5.2 r17328" need upgrade)

St_AddPoint adds the new point always as start point for each value inside the possible valid range. -1 or leaving it out works like expected, maybe due to the correction in #4599.

Attached an example to reproduce the bug.

[Algunenano]

Simpler repro:

# SELECT ST_AsText(ST_AddPoint('LINESTRING(0 0, 1 1, 3 3, 4 4)'::geometry, 'POINT(2 2)'::geometry, 2));
            st_astext            
---------------------------------
 LINESTRING(2 2,0 0,1 1,3 3,4 4)

[Raúl Marín <git@…>]

In b6b33b0d/git:

ST_AddPoint: Fix bug when a positive position is requested

References #4670
Introduced in #4599, so backpatching through 2.5

[Raúl Marín <git@…>]

In c3a45a7/git:

ST_AddPoint: Fix bug when a positive position is requested

References #4670
Introduced in #4599, so backpatching through 2.5

[Raúl Marín <git@…>]

In 10318f5/git:

ST_AddPoint: Fix bug when a positive position is requested

Closes #4670
Introduced in #4599, so backpatching through 2.5

[Algunenano]

It should be fixed now. Thanks for the report.