#1160: documentation clarification of behavior

git-svn-id: http://svn.osgeo.org/postgis/trunk@7755 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_operator.xml b/doc/reference_operator.xml
index 91e7301f65f1179332f9d50cb8141a329735ded1..09a9efec6ed790d539d2378d4c865c62f6d74c16 100644 (file)
--- a/doc/reference_operator.xml
+++ b/doc/reference_operator.xml
@@ -534,7 +534,7 @@ FROM
                  <refnamediv>
                        <refname>&#61;</refname>
 
-                       <refpurpose>Returns <varname>TRUE</varname> if A's bounding box is the same as B's.</refpurpose>
+                       <refpurpose>Returns <varname>TRUE</varname> if A's bounding box is the same as B's. Uses double precision bounding box.</refpurpose>
                  </refnamediv>
 
                  <refsynopsisdiv>
@@ -596,6 +596,10 @@ FROM
                                
                        <para>&curve_support;</para>
                        <para>&P_support;</para>
+                       <para>Changed:  2.0.0 , the bounding box of geometries was changed to use double precision instead of float4 precision of
+                       prior. The side effect of this is that in particular points in prior versions that were a little different may have returned
+                               true in prior versions and false in 2.0+ since their float4 boxes would be the same but there float8 (double precision), would be
+                               different.</para>
 
                  </refsection>
 
@@ -627,7 +631,15 @@ GROUP BY column1;
          st_astext
 ---------------------
  LINESTRING(0 0,1 1)
-(1 row)</programlisting>
+(1 row)
+
+-- In versions prior to 2.0, this used to return true --
+ SELECT ST_GeomFromText('POINT(1707296.37 4820536.77)') =
+       ST_GeomFromText('POINT(1707296.27 4820536.87)') As pt_intersect;
+       
+--pt_intersect --
+f
+</programlisting>
                  </refsection>
 
                  <refsection>