From: Raúl Marín Rodríguez <rmrodriguez@carto.com>
Date: Mon, 1 Oct 2018 15:55:50 +0000 (+0000)
Subject: Avoid division by zero in kmeans
X-Git-Tag: 2.5.1~34
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=af8e22df916220ec480939ad562b60ee064e5472;p=postgis

Avoid division by zero in kmeans

References #4188


git-svn-id: http://svn.osgeo.org/postgis/branches/2.5@16859 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index d2a409a6d..118b6ad7b 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,7 @@ XXXX/XX/XX
 
  * Bug fixes *
   - #4183, St_AsMVTGeom: Drop invalid geometries after simplification (Raúl Marín)
+  - #4188, Avoid division by zero in kmeans (Raúl Marín)
 
 PostGIS 2.5.0
 2018/09/23
diff --git a/liblwgeom/lwkmeans.c b/liblwgeom/lwkmeans.c
index a171f28f3..cbcb28f94 100644
--- a/liblwgeom/lwkmeans.c
+++ b/liblwgeom/lwkmeans.c
@@ -85,8 +85,11 @@ update_means(POINT2D** objs, int* clusters, uint32_t n, POINT2D** centers, uint3
 	}
 	for (i = 0; i < k; i++)
 	{
-		centers[i]->x /= weights[i];
-		centers[i]->y /= weights[i];
+		if (weights[i])
+		{
+			centers[i]->x /= weights[i];
+			centers[i]->y /= weights[i];
+		}
 	}
 }