@turf/unkink-polygon - Fix a potentially unbounded array.push.apply (#2506)

Author: mfedderly

CHANGELOG.md

@@ -45,6 +45,7 @@ We intend to keep making breaking changes before 7.0.0 is fully released. If you
 - [`@turf/points-within-polygon`](points-within-polygon) Fix dropped properties on MultiPoint results (#2227)
 - [`@turf/random`](random) Throws error on invalid bbox inputs (#2172)
 - [`@turf/boolean-parallel`](boolean-parallel) Lines with 180 degree angle between them are also considered parallel (#2475)
+- [`@turf/unkink-polygon`](unkink-polygon) Fix a maximum call stack size exceeded error with very large polygons (#2504)
 
 ## 📖 Documentation
 - [`@turf/bbox`][bbox] Improve documentation (#2153)

packages/turf-unkink-polygon/lib/simplepolygon.js

@@ -44,7 +44,9 @@ export default function (feature) {
     if (!equalArrays(ring[0], ring[ring.length - 1])) {
       ring.push(ring[0]); // Close input ring if it is not
     }
-    vertices.push.apply(vertices, ring.slice(0, ring.length - 1));
+    for (var j = 0; j < ring.length - 1; j++) {
+      vertices.push(ring[j]);
+    }
   }
   if (!isUnique(vertices))
     throw new Error(

packages/turf-unkink-polygon/test.js

@@ -36,6 +36,28 @@ test("unkink-polygon", (t) => {
   t.end();
 });
 
+test("issue #2504", (t) => {
+  // fill coords with a circle with an arbitrary number of points
+  const coords = [];
+  const points = 1000000;
+  for (let i = 0; i < points; i++) {
+    const theta = (i / points) * (2 * Math.PI);
+    coords.push([Math.sin(theta), Math.cos(theta)]);
+  }
+  coords.push(coords[0]);
+
+  try {
+    unkinkPolygon({ type: "Polygon", coordinates: [coords] });
+    t.pass(
+      "large number of coordinates in a single ring should not cause an error"
+    );
+  } catch (e) {
+    t.fail(e);
+  }
+
+  t.end();
+});
+
 test("unkink-polygon -- throws", (t) => {
   var array = [1, 2, 3, 4, 5];
   for (const value in array) {