From 94aac1e2cd2b61070b50c0ca4e925c23393d3e08 Mon Sep 17 00:00:00 2001
From: hpinkos <hannah@cesium.com>
Date: Fri, 12 Jun 2020 13:20:11 -0400
Subject: [PATCH] fixes #8842

---
 Source/Core/WallGeometryLibrary.js |  8 +++--
 Specs/Core/WallGeometrySpec.js     | 49 ++++++++++++++++++++++++++++--
 2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/Source/Core/WallGeometryLibrary.js b/Source/Core/WallGeometryLibrary.js
index ff4fc2a956b9..56181049574c 100644
--- a/Source/Core/WallGeometryLibrary.js
+++ b/Source/Core/WallGeometryLibrary.js
@@ -1,3 +1,5 @@
+import arrayRemoveDuplicates from "./arrayRemoveDuplicates.js";
+import Cartesian3 from "./Cartesian3.js";
 import Cartographic from "./Cartographic.js";
 import defined from "./defined.js";
 import EllipsoidTangentPlane from "./EllipsoidTangentPlane.js";
@@ -13,14 +15,16 @@ var WallGeometryLibrary = {};
 
 function latLonEquals(c0, c1) {
   return (
-    CesiumMath.equalsEpsilon(c0.latitude, c1.latitude, CesiumMath.EPSILON14) &&
-    CesiumMath.equalsEpsilon(c0.longitude, c1.longitude, CesiumMath.EPSILON14)
+    CesiumMath.equalsEpsilon(c0.latitude, c1.latitude, CesiumMath.EPSILON10) &&
+    CesiumMath.equalsEpsilon(c0.longitude, c1.longitude, CesiumMath.EPSILON10)
   );
 }
 
 var scratchCartographic1 = new Cartographic();
 var scratchCartographic2 = new Cartographic();
 function removeDuplicates(ellipsoid, positions, topHeights, bottomHeights) {
+  positions = arrayRemoveDuplicates(positions, Cartesian3.equalsEpsilon, true);
+
   var length = positions.length;
   if (length < 2) {
     return;
diff --git a/Specs/Core/WallGeometrySpec.js b/Specs/Core/WallGeometrySpec.js
index 7ae6c64c155b..ec4ded7d39e3 100644
--- a/Specs/Core/WallGeometrySpec.js
+++ b/Specs/Core/WallGeometrySpec.js
@@ -219,8 +219,53 @@ describe("Core/WallGeometry", function () {
     expect(cartographic.height).toEqualEpsilon(2000.0, CesiumMath.EPSILON8);
   });
 
-  it("does not clean positions that add up past EPSILON14", function () {
-    var eightyPercentOfEpsilon14 = 0.8 * CesiumMath.EPSILON14;
+  it("removes duplicates with very small difference", function () {
+    var w = WallGeometry.createGeometry(
+      new WallGeometry({
+        vertexFormat: VertexFormat.POSITION_ONLY,
+        positions: [
+          new Cartesian3(
+            4347090.215457887,
+            1061403.4237998386,
+            4538066.036525028
+          ),
+          new Cartesian3(
+            4348147.589624987,
+            1043897.8776143644,
+            4541092.234751661
+          ),
+          new Cartesian3(
+            4348147.589882754,
+            1043897.8776762491,
+            4541092.234492364
+          ),
+          new Cartesian3(
+            4335659.882947743,
+            1047571.602084736,
+            4552098.654605664
+          ),
+        ],
+      })
+    );
+
+    var numPositions = 8;
+    var numTriangles = 4;
+    var positions = w.attributes.position.values;
+    expect(positions.length).toEqual(numPositions * 3);
+    expect(w.indices.length).toEqual(numTriangles * 3);
+
+    var cartographic = ellipsoid.cartesianToCartographic(
+      Cartesian3.fromArray(positions, 0)
+    );
+    expect(cartographic.height).toEqualEpsilon(0.0, CesiumMath.EPSILON8);
+
+    cartographic = ellipsoid.cartesianToCartographic(
+      Cartesian3.fromArray(positions, 3)
+    );
+  });
+
+  it("does not clean positions that add up past EPSILON10", function () {
+    var eightyPercentOfEpsilon14 = 0.8 * CesiumMath.EPSILON10;
     var inputPositions = Cartesian3.fromRadiansArrayHeights([
       1.0,
       1.0,