Fix undefined variable (#6699)

diff --git a/src/core/core.scale.js b/src/core/core.scale.js
index 82bd4a2a56c4da08144fcb9af9106f3cdd07a812..c1e589d218a88dd30ff7b08a3431dd818a1da98b 100644 (file)
--- a/src/core/core.scale.js
+++ b/src/core/core.scale.js
@@ -400,7 +400,7 @@ class Scale extends Element {
        */
        _getLabels() {
                var data = this.chart.data;
-               return this.options.labels || (this.isHorizontal() ? data.xLabels : data.yLabels) || data.labels;
+               return this.options.labels || (this.isHorizontal() ? data.xLabels : data.yLabels) || data.labels || [];
        }
 
        // These methods are ordered by lifecyle. Utilities then follow.