From 063adee9404c7a3643fcf10667c0296429a31373 Mon Sep 17 00:00:00 2001
From: Mike Bostock <mbostock@gmail.com>
Date: Wed, 23 May 2018 09:27:24 -0700
Subject: [PATCH] =?UTF-8?q?Don=E2=80=99t=20repeat=20corners.=20Related=20#?=
 =?UTF-8?q?42.?=
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---
 src/voronoi.js       | 14 +++++++-------
 test/voronoi-test.js |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/voronoi.js b/src/voronoi.js
index 76eaadf..1f69e4d 100644
--- a/src/voronoi.js
+++ b/src/voronoi.js
@@ -264,19 +264,19 @@ export default class Voronoi {
   }
   _edge(i, e0, e1, P, j) {
     while (e0 !== e1) {
-      let cx, cy;
+      let x, y;
       switch (e0) {
         case 0b0101: e0 = 0b0100; continue; // top-left
-        case 0b0100: e0 = 0b0110, cx = this.xmax, cy = this.ymin; break; // top
+        case 0b0100: e0 = 0b0110, x = this.xmax, y = this.ymin; break; // top
         case 0b0110: e0 = 0b0010; continue; // top-right
-        case 0b0010: e0 = 0b1010, cx = this.xmax, cy = this.ymax; break; // right
+        case 0b0010: e0 = 0b1010, x = this.xmax, y = this.ymax; break; // right
         case 0b1010: e0 = 0b1000; continue; // bottom-right
-        case 0b1000: e0 = 0b1001, cx = this.xmin, cy = this.ymax; break; // bottom
+        case 0b1000: e0 = 0b1001, x = this.xmin, y = this.ymax; break; // bottom
         case 0b1001: e0 = 0b0001; continue; // bottom-left
-        case 0b0001: e0 = 0b0101, cx = this.xmin, cy = this.ymin; break; // left
+        case 0b0001: e0 = 0b0101, x = this.xmin, y = this.ymin; break; // left
       }
-      if (this.contains(i, cx, cy)) {
-        P.splice(j, 0, cx, cy), j += 2;
+      if ((P[j] !== x || P[j + 1] !== y) && this.contains(i, x, y)) {
+        P.splice(j, 0, x, y), j += 2;
       }
     }
     return j;
diff --git a/test/voronoi-test.js b/test/voronoi-test.js
index 6239b12..38d42f3 100644
--- a/test/voronoi-test.js
+++ b/test/voronoi-test.js
@@ -23,7 +23,7 @@ tape("voronoi.renderCell(i, context) handles midpoint coincident with circumcent
   let voronoi = Delaunay.from([[0, 0], [1, 0], [0, 1]]).voronoi([-1, -1, 2, 2]);
   let context = new Context;
   test.equal((voronoi.renderCell(0, context), context.toString()), `M-1,-1L0.5,-1L0.5,0.5L-1,0.5Z`);
-  test.equal((voronoi.renderCell(1, context), context.toString()), `M2,-1L2,2L2,2L0.5,0.5L0.5,-1Z`);
+  test.equal((voronoi.renderCell(1, context), context.toString()), `M2,-1L2,2L0.5,0.5L0.5,-1Z`);
   test.equal((voronoi.renderCell(2, context), context.toString()), `M-1,2L-1,0.5L0.5,0.5L2,2Z`);
 });