From ef507e11bd6936a0a60cbd66822aa6aef23df828 Mon Sep 17 00:00:00 2001
From: Evert Timberg <evert.timberg+github@gmail.com>
Date: Mon, 11 Feb 2019 13:31:26 -0500
Subject: [PATCH] Handle inextensible `dataset.data` array (#6060)

---
 src/core/core.datasetController.js         |  4 +-
 test/specs/core.datasetController.tests.js | 80 ++++++++++++++++++++++
 2 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/src/core/core.datasetController.js b/src/core/core.datasetController.js
index 6a7d36f196b..afd021c1db1 100644
--- a/src/core/core.datasetController.js
+++ b/src/core/core.datasetController.js
@@ -225,7 +225,9 @@ helpers.extend(DatasetController.prototype, {
 				unlistenArrayEvents(me._data, me);
 			}
 
-			listenArrayEvents(data, me);
+			if (data && Object.isExtensible(data)) {
+				listenArrayEvents(data, me);
+			}
 			me._data = data;
 		}
 
diff --git a/test/specs/core.datasetController.tests.js b/test/specs/core.datasetController.tests.js
index 5ab9dd5f31f..8b5d6dec2e0 100644
--- a/test/specs/core.datasetController.tests.js
+++ b/test/specs/core.datasetController.tests.js
@@ -38,6 +38,86 @@ describe('Chart.DatasetController', function() {
 		});
 	});
 
+	describe('inextensible data', function() {
+		it('should handle a frozen data object', function() {
+			function createChart() {
+				var data = Object.freeze([0, 1, 2, 3, 4, 5]);
+				expect(Object.isExtensible(data)).toBeFalsy();
+
+				var chart = acquireChart({
+					type: 'line',
+					data: {
+						datasets: [{
+							data: data
+						}]
+					}
+				});
+
+				var dataset = chart.data.datasets[0];
+				dataset.data = Object.freeze([5, 4, 3, 2, 1, 0]);
+				expect(Object.isExtensible(dataset.data)).toBeFalsy();
+				chart.update();
+
+				// Tests that the unlisten path also works for frozen objects
+				chart.destroy();
+			}
+
+			expect(createChart).not.toThrow();
+		});
+
+		it('should handle a sealed data object', function() {
+			function createChart() {
+				var data = Object.seal([0, 1, 2, 3, 4, 5]);
+				expect(Object.isExtensible(data)).toBeFalsy();
+
+				var chart = acquireChart({
+					type: 'line',
+					data: {
+						datasets: [{
+							data: data
+						}]
+					}
+				});
+
+				var dataset = chart.data.datasets[0];
+				dataset.data = Object.seal([5, 4, 3, 2, 1, 0]);
+				expect(Object.isExtensible(dataset.data)).toBeFalsy();
+				chart.update();
+
+				// Tests that the unlisten path also works for frozen objects
+				chart.destroy();
+			}
+
+			expect(createChart).not.toThrow();
+		});
+
+		it('should handle an unextendable data object', function() {
+			function createChart() {
+				var data = Object.preventExtensions([0, 1, 2, 3, 4, 5]);
+				expect(Object.isExtensible(data)).toBeFalsy();
+
+				var chart = acquireChart({
+					type: 'line',
+					data: {
+						datasets: [{
+							data: data
+						}]
+					}
+				});
+
+				var dataset = chart.data.datasets[0];
+				dataset.data = Object.preventExtensions([5, 4, 3, 2, 1, 0]);
+				expect(Object.isExtensible(dataset.data)).toBeFalsy();
+				chart.update();
+
+				// Tests that the unlisten path also works for frozen objects
+				chart.destroy();
+			}
+
+			expect(createChart).not.toThrow();
+		});
+	});
+
 	it('should synchronize metadata when data are inserted or removed', function() {
 		var data = [0, 1, 2, 3, 4, 5];
 		var chart = acquireChart({