From: Bruce Momjian <bruce@momjian.us>
Date: Mon, 24 Feb 2014 17:24:00 +0000 (-0500)
Subject: Allow single-point polygons to be converted to circles
X-Git-Tag: REL9_4_BETA1~427
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=423f69ab64a6e51fbdd97a83c1dc55d68ca6190d;p=thirdparty%2Fpostgresql.git

Allow single-point polygons to be converted to circles

This allows finding the center of a single-point polygon and converting
it to a point.

Per report from Josef Grahn
---

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index f267920649a..72cb4e991fc 100644
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -5191,7 +5191,7 @@ poly_circle(PG_FUNCTION_ARGS)
 	CIRCLE	   *circle;
 	int			i;
 
-	if (poly->npts < 2)
+	if (poly->npts < 1)
 		ereport(ERROR,
 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
 				 errmsg("cannot convert empty polygon to circle")));
@@ -5214,11 +5214,6 @@ poly_circle(PG_FUNCTION_ARGS)
 		circle->radius += point_dt(&poly->p[i], &circle->center);
 	circle->radius /= poly->npts;
 
-	if (FPzero(circle->radius))
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-				 errmsg("cannot convert empty polygon to circle")));
-
 	PG_RETURN_CIRCLE_P(circle);
 }