1 files changed, 49 insertions, 19 deletions
diff --git a/js/src/builtin/intl/CommonFunctions.js b/js/src/builtin/intl/CommonFunctions.js
index effabf020f..69b96d6db1 100644
--- a/js/src/builtin/intl/CommonFunctions.js
+++ b/js/src/builtin/intl/CommonFunctions.js
@@ -647,33 +647,63 @@ function GetOption(options, property, type, values, fallback) {
     return fallback;
 }
 
+
 /**
- * Extracts a property value from the provided options object, converts it to a
- * Number value, checks whether it is in the allowed range, and fills in a
- * fallback value if necessary.
+ * The abstract operation DefaultNumberOption converts value to a Number value,
+ * checks whether it is in the allowed range, and fills in a fallback value if
+ * necessary.
  *
- * Spec: ECMAScript Internationalization API Specification, 9.2.10.
+ * Spec: ECMAScript Internationalization API Specification, 9.2.11.
  */
-function GetNumberOption(options, property, minimum, maximum, fallback) {
-    assert(typeof minimum === "number", "GetNumberOption");
-    assert(typeof maximum === "number", "GetNumberOption");
-    assert(fallback === undefined || (fallback >= minimum && fallback <= maximum), "GetNumberOption");
+function DefaultNumberOption(value, minimum, maximum, fallback) {
+  assert(
+    typeof minimum === "number" && (minimum | 0) === minimum,
+    "DefaultNumberOption"
+  );
+  assert(
+    typeof maximum === "number" && (maximum | 0) === maximum,
+    "DefaultNumberOption"
+  );
+  assert(
+    fallback === undefined ||
+      (typeof fallback === "number" && (fallback | 0) === fallback),
+    "DefaultNumberOption"
+  );
+  assert(
+    fallback === undefined || (minimum <= fallback && fallback <= maximum),
+    "DefaultNumberOption"
+  );
+
+  // Step 1.
+  if (value === undefined) {
+    return fallback;
+  }
 
-    // Step 1.
-    var value = options[property];
+  // Step 2.
+  value = ToNumber(value);
 
-    // Step 2.
-    if (value !== undefined) {
-        value = ToNumber(value);
-        if (Number_isNaN(value) || value < minimum || value > maximum)
-            ThrowRangeError(JSMSG_INVALID_DIGITS_VALUE, value);
-        return std_Math_floor(value);
-    }
+  // Step 3.
+  if (Number_isNaN(value) || value < minimum || value > maximum) {
+    ThrowRangeError(JSMSG_INVALID_DIGITS_VALUE, value);
+  }
 
-    // Step 3.
-    return fallback;
+  // Step 4.
+  // Apply bitwise-or to convert -0 to +0 per ES2017, 5.2 and to ensure the
+  // result is an int32 value.
+  return std_Math_floor(value) | 0;
 }
 
+/**
+ * Extracts a property value from the provided options object, converts it to a
+ * Number value, checks whether it is in the allowed range, and fills in a
+ * fallback value if necessary.
+ *
+ * Spec: ECMAScript Internationalization API Specification, 9.2.12.
+ */
+function GetNumberOption(options, property, minimum, maximum, fallback) {
+    // Steps 1-3.
+    return DefaultNumberOption(options[property], minimum, maximum, fallback);
+}
 
 // Symbols in the self-hosting compartment can't be cloned, use a separate
 // object to hold the actual symbol value.