From dbc537d6e7d9f9bdf87df389b4abf2195409f9a7 Mon Sep 17 00:00:00 2001
From: Martin Davis <mtnclimb@gmail.com>
Date: Fri, 11 Oct 2024 12:24:05 -0700
Subject: [PATCH] Fix equalsTopo predicate for empty

---
 .../jts/operation/relateng/RelatePredicate.java       | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelatePredicate.java b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelatePredicate.java
index 87d9f51b53..7802be5a9b 100644
--- a/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelatePredicate.java
+++ b/modules/core/src/main/java/org/locationtech/jts/operation/relateng/RelatePredicate.java
@@ -482,11 +482,20 @@ public static TopologyPredicate equalsTopo() {
       @Override
       public void init(int dimA, int dimB) {
         super.init(dimA, dimB);
-        require(dimA == dimB);
+        //-- don't require equal dims, because EMPTY = EMPTY for all dims
       }
       
+      @Override
+      public boolean requireInteraction() {
+        //-- allow EMPTY = EMPTY
+        return false;
+      };
+    
       @Override
       public void init(Envelope envA, Envelope envB) {
+        //-- handle EMPTY = EMPTY cases
+        setValueIf(true, envA.isNull() && envB.isNull());
+        
         require(envA.equals(envB));
       }