From 5d014027e72d064a43dbf5ae1f27012e06661759 Mon Sep 17 00:00:00 2001
From: Paul Ramsey <pramsey@cleverelephant.ca>
Date: Fri, 2 Nov 2012 19:15:05 +0000
Subject: [PATCH] #1996, ST_AsGeoJSON('POINT EMPTY') produces invalid JSON

git-svn-id: http://svn.osgeo.org/postgis/trunk@10628 b70326c6-7e19-0410-871a-916f4a2858ee
---
 NEWS                      | 1 +
 liblwgeom/lwout_geojson.c | 5 +++++
 regress/tickets.sql       | 3 +++
 regress/tickets_expected  | 1 +
 4 files changed, 10 insertions(+)

diff --git a/NEWS b/NEWS
index 5fcaf4ef5..bae94c8b4 100644
--- a/NEWS
+++ b/NEWS
@@ -94,6 +94,7 @@ PostGIS 2.1.0
   - #1957, ST_Distance to a one-point LineString returns NULL 
   - #1976, Geography point-in-ring code overhauled for more reliability
   - #1981, cleanup of unused variables causing warnings with gcc 4.6+
+  - #1996, support POINT EMPTY in GeoJSON output
   - #2026, improve performance of distance calculations 
   - #2057, Fixed linking issue for raster2psql to libpq
   - #2077, Fixed incorrect values returning from ST_Hillshade()
diff --git a/liblwgeom/lwout_geojson.c b/liblwgeom/lwout_geojson.c
index 015dc8bc6..f7ec7e49c 100644
--- a/liblwgeom/lwout_geojson.c
+++ b/liblwgeom/lwout_geojson.c
@@ -158,6 +158,9 @@ asgeojson_point_size(const LWPOINT *point, char *srs, GBOX *bbox, int precision)
 	size += sizeof("{'type':'Point',");
 	size += sizeof("'coordinates':}");
 
+	if ( lwpoint_is_empty(point) )
+		size += 2; /* [] */
+
 	if (srs) size += asgeojson_srs_size(srs);
 	if (bbox) size += asgeojson_bbox_size(FLAGS_GET_Z(point->flags), precision);
 
@@ -174,6 +177,8 @@ asgeojson_point_buf(const LWPOINT *point, char *srs, char *output, GBOX *bbox, i
 	if (bbox) ptr += asgeojson_bbox_buf(ptr, bbox, FLAGS_GET_Z(point->flags), precision);
 
 	ptr += sprintf(ptr, "\"coordinates\":");
+	if ( lwpoint_is_empty(point) )
+		ptr += sprintf(ptr, "[]");
 	ptr += pointArray_to_geojson(point->point, ptr, precision);
 	ptr += sprintf(ptr, "}");
 
diff --git a/regress/tickets.sql b/regress/tickets.sql
index 919f854b5..dfe241069 100644
--- a/regress/tickets.sql
+++ b/regress/tickets.sql
@@ -725,5 +725,8 @@ SELECT '#1957', ST_Distance(ST_Makeline(ARRAY['POINT(1 0)'::geometry]), 'POINT(0
 -- #1978 --
 SELECT '#1978', round(ST_Length(ST_GeomFromText('CIRCULARSTRING(0 0,1 0,0 0)',0))::numeric,4);
 
+-- #1996 --
+SELECT '#1996', ST_AsGeoJSON(ST_GeomFromText('POINT EMPTY'));
+
 -- Clean up
 DELETE FROM spatial_ref_sys;
diff --git a/regress/tickets_expected b/regress/tickets_expected
index 4ce2d2b3f..afc2ee9a6 100644
--- a/regress/tickets_expected
+++ b/regress/tickets_expected
@@ -228,3 +228,4 @@ ERROR:  ST_Segmentize: invalid max_distance 0 (must be >= 0)
 ERROR:  invalid GML representation
 #1957|1
 #1978|3.1413
+#1996|{"type":"Point","coordinates":[]}
-- 
2.40.0