Improve release notes' description of Teodor's fixes for polygon overlaps

and contains operators.

diff --git a/doc/src/sgml/release-9.0.sgml b/doc/src/sgml/release-9.0.sgml
index 31102a21b9e51d7836ba9a58097735450be826bf..7bfdf1419b09a33f20dc6bfacaf5d303df4ee2cd 100644 (file)
--- a/doc/src/sgml/release-9.0.sgml
+++ b/doc/src/sgml/release-9.0.sgml
@@ -1,4 +1,4 @@
-
+
 
  
   Release 9.0
@@ -1698,8 +1698,19 @@
     
      
       Correct calculations of 
-      linkend="functions-geometry-op-table">overlap
-      and contains operations over polygons (Teodor Sigaev)
+      linkend="functions-geometry-op-table">overlaps
+      and contains operations for polygons (Teodor Sigaev)
+     
+
+     
+      The polygon && (overlaps) operator formerly just
+      checked to see if the two polygons' bounding boxes overlapped.  It now
+      does a more correct check.  The polygon @> and
+      <@ (contains/contained by) operators formerly checked
+      to see if one polygon's vertexes were all contained in the other;
+      this can wrongly report true for some non-convex polygons.
+      Now they check that all line segments of one polygon are contained in
+      the other.