Classes that define Equals must implement hashCode with matching behavior

jts-hashcode.patch

--- old/java/com/vividsolutions/jts/geom/PrecisionModel.java
+++ new/java/com/vividsolutions/jts/geom/PrecisionModel.java
@@ -1,5 +1,3 @@
-
-
 /*
  * The JTS Topology Suite is a collection of Java classes that
  * implement the fundamental operations required to validate a given
@@ -37,6 +35,7 @@
 import java.io.Serializable;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * Specifies the precision model of the {@link Coordinate}s in a {@link Geometry}.
@@ -438,6 +437,12 @@
   	}
   	return description;
   }
+
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(modelType, scale);
+  }
 
   public boolean equals(Object other) {
     if (! (other instanceof PrecisionModel)) {
--- old/java/com/vividsolutions/jts/geom/util/AffineTransformation.java
+++ new/java/com/vividsolutions/jts/geom/util/AffineTransformation.java
@@ -35,6 +35,8 @@
 
 import com.vividsolutions.jts.geom.*;
 import com.vividsolutions.jts.util.*;
+import java.util.Objects;
+
 /**
  * Represents an affine transformation on the 2D Cartesian plane. 
  * It can be used to transform a {@link Coordinate} or {@link Geometry}.
@@ -1080,7 +1082,14 @@
     && m11 == trans.m11
     && m12 == trans.m12;
   }
+
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(m00, m01, m02, m10, m11, m12);
+  }
+
   /**
    * Gets a text representation of this transformation.
    * The string is of the form:
    * <pre>
--- old/java/com/vividsolutions/jts/geomgraph/Edge.java
+++ new/java/com/vividsolutions/jts/geomgraph/Edge.java
@@ -1,6 +1,3 @@
-
-
-
 /*
  * The JTS Topology Suite is a collection of Java classes that
  * implement the fundamental operations required to validate a given
@@ -36,14 +33,15 @@
 package com.vividsolutions.jts.geomgraph;
 
 import java.io.PrintStream;
+import java.util.Arrays;
 import java.util.Iterator;
+import java.util.Objects;
 import com.vividsolutions.jts.algorithm.LineIntersector;
 import com.vividsolutions.jts.geom.*;
 import com.vividsolutions.jts.util.*;
 import com.vividsolutions.jts.geomgraph.*;
 import com.vividsolutions.jts.geomgraph.index.*;
 
-
 /**
  * @version 1.7
  */
@@ -241,6 +239,15 @@
     }
     return true;
   }
+
+  @Override
+  public int hashCode()
+  {
+    // Correct, but not optimal.
+    Coordinate[] sorted = pts.clone();
+    Arrays.sort(sorted);
+    return Arrays.hashCode(sorted);
+  }
 
   /**
    * @return true if the coordinate sequences of the Edges are identical
--- old/java/com/vividsolutions/jts/index/strtree/Interval.java
+++ new/java/com/vividsolutions/jts/index/strtree/Interval.java
@@ -34,6 +34,7 @@
 package com.vividsolutions.jts.index.strtree;
 
 import com.vividsolutions.jts.util.*;
+import java.util.Objects;
 
 /**
  * A contiguous portion of 1D-space. Used internally by SIRtree.
@@ -75,4 +76,11 @@
     Interval other = (Interval) o;
     return min == other.min && max == other.max;
   }
+
+  @Override
+  public int hashCode()
+  {
+    return Objects.hash(min, max);
+  }
+
 }