From: Paul Ramsey <pramsey@cleverelephant.ca>
Date: Wed, 5 Jun 2013 21:01:48 +0000 (+0000)
Subject: #2168, ST_Distance is not always commutative
X-Git-Tag: 2.1.0beta3~15
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=193f790857454a6a2115255222a835d6089b028f;p=postgis

#2168, ST_Distance is not always commutative


git-svn-id: http://svn.osgeo.org/postgis/trunk@11530 b70326c6-7e19-0410-871a-916f4a2858ee
---

diff --git a/NEWS b/NEWS
index 491223172..97f8e023b 100644
--- a/NEWS
+++ b/NEWS
@@ -185,6 +185,7 @@ PostGIS 2.1.0
   - #2100, ST_AsRaster may not return raster with specified pixel type
   - #2126, Better handling of empty rasters from ST_ConvexHull()
   - #2165, ST_NumPoints regression failure with CircularString
+  - #2168, ST_Distance is not always commutative
   - #2182, Fix issue with outdb rasters with no SRID and ST_Resize
   - #2188, Fix function parameter value overflow that caused problems
            when copying data from a GDAL dataset
diff --git a/postgis/geography_measurement.c b/postgis/geography_measurement.c
index 952ddefe5..5dec9ffc3 100644
--- a/postgis/geography_measurement.c
+++ b/postgis/geography_measurement.c
@@ -169,6 +169,9 @@ Datum geography_distance(PG_FUNCTION_ARGS)
 		PG_RETURN_NULL();
 	}
 
+    /* Knock off any funny business at the micrometer level, ticket #2168 */
+    distance = round(distance * 10e8) / 10e8;
+
 	PG_RETURN_FLOAT8(distance);
 }