Some fixes to Math.pow.

runtime/lib/double.dart

Index: runtime/lib/double.dart
===================================================================
--- runtime/lib/double.dart	(revision 4834)
+++ runtime/lib/double.dart	(working copy)
@@ -112,7 +112,15 @@
   double toDouble() { return this; }
 
   double pow(num exponent) {
-    return _pow(exponent.toDouble());
+    if (exponent == 0) {
+      return 1.0;  // ECMA-262 15.8.2.13

[ngeoffray, 2012/03/02 07:55:47]

Wouldn't it be better to point to Dart spec instead? and the Dart spec listing
all these cases (even if the text explaining is missing).

[srdjan, 2012/03/02 17:55:37]

Good point. There is no Dart library spec for "pow" yet and I will file a
request for it. The comment says that the implementation does implement what
ECMA-262 says. I think it is helpful in the way that it does not seem
arbitrarily.
 

+    }
+    // Throw NullPointerException if exponent is null.
+    double doubleExponent = exponent.toDouble();
+    if (isNaN() || exponent.isNaN()) {
+      return double.NAN;
+    }
+    return _pow(doubleExponent);
   }
   double _pow(double exponent) native "Double_pow";