Fix: make string indexing work with Infinity.

src/runtime.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5269 matching lines @@
   CONVERT_DOUBLE_CHECKED(number, args[0]);
 
   // We do not include 0 so that we don't have to treat +0 / -0 cases.
   if (number > 0 && number <= Smi::kMaxValue) {
     return Smi::FromInt(static_cast<int>(number));
   }
   return Heap::NumberFromDouble(DoubleToInteger(number));
 }
 
 
+static Object* Runtime_NumberToIntegerMapMinusZero(Arguments args) {
+  NoHandleAllocation ha;
+  ASSERT(args.length() == 1);
+
+  CONVERT_DOUBLE_CHECKED(number, args[0]);
+
+  // We do not include 0 so that we don't have to treat +0 / -0 cases.
+  if (number > 0 && number <= Smi::kMaxValue) {
+    return Smi::FromInt(static_cast<int>(number));
+  }
+
+  double double_value = DoubleToInteger(number);
+  // Map both -0 and +0 to +0.
+  if (double_value == 0) double_value = 0;
+
+  return Heap::NumberFromDouble(double_value);
+}
+
+
 static Object* Runtime_NumberToJSUint32(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 1);
 
   CONVERT_NUMBER_CHECKED(int32_t, number, Uint32, args[0]);
   return Heap::NumberFromUint32(number);
 }
 
 
 static Object* Runtime_NumberToJSInt32(Arguments args) {
@@ skipping 4929 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     Counters::gc_last_resort_from_js.Increment();
     Heap::CollectAllGarbage(false);
   }
 }
 
 
 } }  // namespace v8::internal