Document new ST_CollectionExtract behavior

git-svn-id: http://svn.osgeo.org/postgis/trunk@8722 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_editor.xml b/doc/reference_editor.xml
index 874e306528c07a5678c9a3dbd136ee12df2b957e..0c199daba840d9e76bc463f5eaf01e18d70df3d2 100644 (file)
--- a/doc/reference_editor.xml
+++ b/doc/reference_editor.xml
@@ -645,9 +645,11 @@ MULTILINESTRING((-45.2 -33.2,-46 -32),(-29 -27,-30 -29.7,-36 -31,-45 -33))
                <refnamediv>
                        <refname>ST_CollectionExtract</refname>
 
-                       <refpurpose>Given a GEOMETRYCOLLECTION, returns a MULTI* geometry consisting only of the specified type. Sub-geometries that are not
-                           the specified type are ignored. If there are no sub-geometries of the right type, an EMPTY collection will be returned. Only
-                           points, lines and polygons are supported. Type numbers are 1 == POINT, 2 == LINESTRING, 3 == POLYGON.</refpurpose>
+                       <refpurpose>
+Given a (multi)geometry, returns a (multi)geometry consisting only of elements of the specified type.
+Sub-geometries that are not the specified type are ignored. If there are no sub-geometries of the right type, an EMPTY geometry will be returned.
+Only points, lines and polygons are supported. Type numbers are 1 == POINT, 2 == LINESTRING, 3 == POLYGON.
+                       </refpurpose>
                </refnamediv>
 
                <refsynopsisdiv>
@@ -663,12 +665,20 @@ MULTILINESTRING((-45.2 -33.2,-46 -32),(-29 -27,-30 -29.7,-36 -31,-45 -33))
                <refsection>
                        <title>Description</title>
 
-                       <para>Given a GEOMETRYCOLLECTION, returns a MULTI* geometry consisting only of the specified type. Sub-geometries that are not
-                           the specified type are ignored. If there are no sub-geometries of the right type, an EMPTY collection will be returned. Only
-                           points, lines and polygons are supported. Type numbers are 1 == POINT, 2 == LINESTRING, 3 == POLYGON.</para>
+                       <para>
+Given a (multi)geometry, returns a (multi)geometry consisting only of elements of the specified type.
+Sub-geometries that are not the specified type are ignored. If there are no sub-geometries of the right type, an EMPTY geometry will be returned.
+Only points, lines and polygons are supported. Type numbers are 1 == POINT, 2 == LINESTRING, 3 == POLYGON.
+                       </para>
 
                        <para>Availability: 1.5.0</para>
-                       
+
+                       <note><para>
+Prior to 1.5.3 this function returned non-collection inputs untouched, no matter type.
+In 1.5.3 non-matching single geometries result in a NULL return. 
+In of 2.0.0 every case of missing match results in a typed EMPTY return.
+                       </para></note>
+
                </refsection>
 
                <refsection>