Fix "illegal access" when calling parseInt with a radix that is not a smi.

src/v8natives.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
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@@ skipping 88 matching lines @@
     // vs 800ns).  The following optimization makes parseInt on a
     // non-Smi number 9 times faster (230ns vs 2070ns).  Together
     // they make parseInt on a string 1.4% slower (274ns vs 270ns).
     if (%_IsSmi(string)) return string;
     if (IS_NUMBER(string) &&
         ((0.01 < string && string < 1e9) ||
             (-1e9 < string && string < -0.01))) {
       // Truncate number.
       return string | 0;
     }
-    if (IS_UNDEFINED(radix)) radix = 0;
+    radix = radix || 0;

[Lasse Reichstein, 2011/06/28 08:32:21]

This seems silly to begin with. Just set 
 radix = 0;
It means the same as radix 10, so the rest of the function will work the same,
and it seems we optimize the code for 0 over 10.
 

[Steven, 2011/06/28 10:10:35]

It seems so but it's not: 'radix = 0' will trigger radix detection what you
don't want in the case 'radix == 10'.
On 2011/06/28 08:32:21, Lasse Reichstein wrote:

[Lasse Reichstein, 2011/06/28 10:28:17]

Ack, my bad.
In that case, use
 radix = TO_INT32(radix);
Or, if it's faster (it probably is), just:
 radix = radix | 0;
Both will convert to Int32, which converts both undefined and -0 to 0.
Using || 0 is likely to be slower, since it contains an implicity branch.

[Lasse Reichstein, 2011/06/28 10:31:48]

and because  radix = radix || 0  would not convert a HeapNumber containing 10 to
a smi.

If possible, add a test where the number is a heap-number value equal to 10 (but
it's hard to guarantee the underlying representation, try something like
Math.ln(Math.exp(10)) and cross your fingers).

   } else {
     radix = TO_INT32(radix);
     if (!(radix == 0 || (2 <= radix && radix <= 36)))
       return $NaN;

[Lasse Reichstein, 2011/06/28 08:32:21]

Could you please put braces around the then-branch of this if while you are
here.

[Steven, 2011/06/28 10:10:35]

Done.

   }
   string = TO_STRING_INLINE(string);
   if (%_HasCachedArrayIndex(string) &&
       (radix == 0 || radix == 10)) {
     return %_GetCachedArrayIndex(string);
   }
   return %StringParseInt(string, radix);
 }
 
 
@@ skipping 1266 matching lines @@
 // ----------------------------------------------------------------------------
 
 function SetupFunction() {
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetupFunction();