update InteriorRingN doc

git-svn-id: http://svn.osgeo.org/postgis/trunk@1212 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/postgis.xml b/doc/postgis.xml
index ed9de97243a1e642a887911dd85d4b17f62d919d..7f86fa6476731b7c73612ca445f29e6e28b11bc9 100644 (file)
--- a/doc/postgis.xml
+++ b/doc/postgis.xml
@@ -3069,9 +3069,9 @@ dimension
             <term>InteriorRingN(geometry,integer)</term>
 
             <listitem>
-              <para>Return the N'th interior ring of the first polygon in the
-              geometry. Return NULL if there is no polygon in the
-              geometry.</para>
+              <para>Return the N'th interior ring of the polygon geometry.
+             Return NULL if the geometry is not a polygon or the given
+             N is out of range (1-based).</para>
             </listitem>
           </varlistentry>