Merge branch '1.6' into 1.7

Author: Zhen Li

package.json

@@ -51,13 +51,13 @@
     "gulp-util": "^3.0.6",
     "gulp-watch": "^4.3.5",
     "jasmine-console-reporter": "^2.0.1",
-    "karma": "^1.7.1",
+    "karma": "^2.0.3",
     "karma-chrome-launcher": "^2.2.0",
     "karma-edge-launcher": "^0.4.2",
-    "karma-firefox-launcher": "^1.0.1",
+    "karma-firefox-launcher": "^1.1.0",
     "karma-ie-launcher": "^1.0.0",
-    "karma-jasmine": "^1.1.0",
-    "karma-spec-reporter": "^0.0.31",
+    "karma-jasmine": "^1.1.2",
+    "karma-spec-reporter": "^0.0.32",
     "lodash": "^4.17.4",
     "lolex": "^1.5.2",
     "minimist": "^1.2.0",

src/v1/internal/temporal-util.js

@@ -383,7 +383,13 @@ function formatNumber(num, stringLength = undefined) {
   if (isNegative) {
     num = num.negate();
   }
-  const numString = num.toString();
-  const paddedNumString = stringLength ? numString.padStart(stringLength, '0') : numString;
-  return isNegative ? '-' + paddedNumString : paddedNumString;
+
+  let numString = num.toString();
+  if (stringLength) {
+    // left pad the string with zeroes
+    while (numString.length < stringLength) {
+      numString = '0' + numString;
+    }
+  }
+  return isNegative ? '-' + numString : numString;
 }