Negative numbers should not be >>> shifted.

lib/compiler/implementation/lib/js_helper.dart

Index: lib/compiler/implementation/lib/js_helper.dart
diff --git a/lib/compiler/implementation/lib/js_helper.dart b/lib/compiler/implementation/lib/js_helper.dart
index c46f2f42b49b0d96f54c624576d92c45da2c46ba..e8e0497ba1051b052f4a149bf011b1af0098c30d 100644
--- a/lib/compiler/implementation/lib/js_helper.dart
+++ b/lib/compiler/implementation/lib/js_helper.dart
@@ -178,7 +178,8 @@ shr(var a, var b) {
     // JavaScript only looks at the last 5 bits of the shift-amount. Shifting
     // by 33 is hence equivalent to a shift by 1.
     if (b > 31) return 0;
-    return JS('num', @'# >>> #', a, b);
+    if (a >= 0) return JS('num', @'# >>> #', a, b);
+    return JS('num', @'(# >> #) >>> 0', a, b);

[ngeoffray, 2012/05/22 15:46:31]

Please add a comment on what this entails.

[floitsch, 2012/05/22 21:07:37]

Done.

   }
   return UNINTERCEPTED(a >> b);
 }