prestodb/presto

ST_Centroid (Java) does not comply with ISO spec

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#26947 opened on Jan 12, 2026

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 (3 comments) (0 reactions) (0 assignees)Java (15,558 stars) (5,240 forks)batch import
buggood first issue

Description

In the ISO spec, ST_Centroid(empty_geometry) returns NULL, but in the Java code it returns an empty geometry. This is fixed for Velox/native in https://github.com/facebookincubator/velox/pull/15985 , but should also be fixed in Java.

Expected Behavior

ST_Centroid(ST_GeometryFromText('LINESTRING EMPTY')) IS NULL

Current Behavior

ST_IsEmpty(ST_Centroid(ST_GeometryFromText('LINESTRING EMPTY')))

Possible Solution

The ST_Centroid function should check for an empty input geometry and return null.

Steps to Reproduce

SELECT ST_Centroid(ST_GeometryFromText('LINESTRING EMPTY'))

Contributor guide

Tech stack
java
Domain
databasebackend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaSQL geometry functions
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
80
Research direction
The issue references a fix in Velox (https://github.com/facebookincubator/velox/pull/15985). The Java implementation of ST Centroid likely lives in the presto geospatial module. Locate the ST Centroid function, add a check for empty geometry input, and return null as per ISO spec. Review the existing test cases for spatial functions to ensure proper coverage.