Ensure GeometryFixer does not change coordinate dimension

modules/core/src/main/java/org/locationtech/jts/algorithm/RobustLineIntersector.java

@@ -214,11 +214,11 @@ private static Coordinate copyWithZ(Coordinate p, double z) {
     if (! Double.isNaN(z)) {
       pCopy.setZ( z );
     }
-    return pCopy;    
+    return pCopy;
   }
 
   private static Coordinate copy(Coordinate p) {
-    return new Coordinate(p);    
+    return p.copy();
   }
 
   /**

modules/core/src/main/java/org/locationtech/jts/noding/NodedSegmentString.java

@@ -164,7 +164,7 @@ public void addIntersections(LineIntersector li, int segmentIndex, int geomIndex
    */
   public void addIntersection(LineIntersector li, int segmentIndex, int geomIndex, int intIndex)
   {
-    Coordinate intPt = new Coordinate(li.getIntersection(intIndex));
+    Coordinate intPt = li.getIntersection(intIndex).copy();
     addIntersection(intPt, segmentIndex);
   }
 

modules/core/src/main/java/org/locationtech/jts/noding/SegmentNode.java

@@ -31,7 +31,7 @@ public class SegmentNode
 
   public SegmentNode(NodedSegmentString segString, Coordinate coord, int segmentIndex, int segmentOctant) {
     this.segString = segString;
-    this.coord = new Coordinate(coord);
+    this.coord = coord.copy();
     this.segmentIndex = segmentIndex;
     this.segmentOctant = segmentOctant;
     isInterior = ! coord.equals2D(segString.getCoordinate(segmentIndex));

modules/core/src/main/java/org/locationtech/jts/noding/SegmentNodeList.java

@@ -255,11 +255,11 @@ private Coordinate[] createSplitEdgePts(SegmentNode ei0, SegmentNode ei1) {
 
     Coordinate[] pts = new Coordinate[npts];
     int ipt = 0;
-    pts[ipt++] = new Coordinate(ei0.coord);
+    pts[ipt++] = ei0.coord.copy();
     for (int i = ei0.segmentIndex + 1; i <= ei1.segmentIndex; i++) {
       pts[ipt++] = edge.getCoordinate(i);
     }
-    if (useIntPt1) pts[ipt] = new Coordinate(ei1.coord);
+    if (useIntPt1) pts[ipt] = ei1.coord.copy();
     return pts;
   }
 

modules/core/src/main/java/org/locationtech/jts/operation/buffer/OffsetCurveBuilder.java

@@ -163,7 +163,7 @@ private static Coordinate[] copyCoordinates(Coordinate[] pts)
   {
     Coordinate[] copy = new Coordinate[pts.length];
     for (int i = 0; i < copy.length; i++) {
-      copy[i] = new Coordinate(pts[i]);
+      copy[i] = pts[i].copy();
     }
     return copy;
   }
@@ -177,7 +177,7 @@ private OffsetSegmentGenerator getSegGen(double distance)
    * Computes the distance tolerance to use during input
    * line simplification.
    * 
-   * @param distance the buffer distance
+   * @param bufDistance the buffer distance
    * @return the simplification tolerance
    */
   private double simplifyTolerance(double bufDistance)

modules/core/src/test/java/org/locationtech/jts/geom/util/GeometryFixerTest.java

@@ -12,10 +12,12 @@
 package org.locationtech.jts.geom.util;
 
 import org.locationtech.jts.geom.Coordinate;
+import org.locationtech.jts.geom.CoordinateArrays;
 import org.locationtech.jts.geom.Geometry;
 import org.locationtech.jts.geom.Point;
 
 import junit.textui.TestRunner;
+import org.locationtech.jts.io.WKTReader;
 import test.jts.GeometryTestCase;
 
 public class GeometryFixerTest extends GeometryTestCase {
@@ -344,7 +346,25 @@ public void testIssue852Case2() {
     checkFix("POLYGON ((50.69544005538049 4.587126197745181, 50.699035986722194 4.592752502415541, 50.699395579856365 4.592049214331746, 50.699125885005735 4.590501980547397, 50.69867639358802 4.591064611014433, 50.69795720731968 4.591064611014433, 50.69759761418551 4.590501980547397, 50.69759761418551 4.589376719613325, 50.69831680045385 4.588251458679252, 50.69723802105134 4.586563567278144, 50.69579964851466 4.586563567278144, 50.69544005538049 4.587126197745181))");
   }
 
-
+  //----------------------------------------
+  public void testDimensionConsistence(){
+    // test 2d case
+    WKTReader reader = new WKTReader();
+    reader.setIsOldJtsCoordinateSyntaxAllowed(false);
+    Geometry geom2d = read(reader, "POLYGON((0 0, 1 0.1, 1 1, 0.5 1, 0.5 1.5, 1 1, 1.5 1.5, 1.5 1, 1 1, 1.5 0.5, 1 0.1, 2 0, 2 2,0 2, 0 0))");
+    assertEquals(2, CoordinateArrays.dimension(geom2d.getCoordinates()));
+
+    Geometry fix2d = GeometryFixer.fix(geom2d);
+    assertEquals(2, CoordinateArrays.dimension(fix2d.getCoordinates()));
+
+    // test 3d case
+    Geometry geom3d = read(reader, "POLYGON Z ((10 90 1, 60 90 6, 60 10 6, 10 10 1, 10 90 1), (20 80 2, 90 80 9, 90 20 9, 20 20 2, 20 80 2))");
+    assertEquals(3, CoordinateArrays.dimension(geom3d.getCoordinates()));
+
+    Geometry fix3d = GeometryFixer.fix(geom3d);
+    assertEquals(3, CoordinateArrays.dimension(fix3d.getCoordinates()));
+  }
+
   //================================================
 
   private void checkFix(String wkt) {