d8 external array c'tors: allow parameters that can be converted to numbers

BUG=v8:1681
TEST=d8 accepts: var a = new Int32Array("2");

Review URL: http://codereview.chromium.org/7867036

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9243 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/d8.cc

@@ -295,8 +295,12 @@ Handle<Value> Shell::CreateExternalArray(const Arguments& args,
   size_t length = 0;
   if (args[0]->IsUint32()) {
     length = args[0]->Uint32Value();
-  } else if (args[0]->IsNumber()) {
-    double raw_length = args[0]->NumberValue();
+  } else {
+    Local<Number> number = args[0]->ToNumber();
+    if (number.IsEmpty() || !number->IsNumber()) {
+      return ThrowException(String::New("Array length must be a number."));
+    }
+    double raw_length = number->NumberValue();
     if (raw_length < 0) {
       return ThrowException(String::New("Array length must not be negative."));
     }
@@ -305,8 +309,6 @@ Handle<Value> Shell::CreateExternalArray(const Arguments& args,
           String::New("Array length exceeds maximum length."));
     }
     length = static_cast<size_t>(raw_length);
-  } else {
-    return ThrowException(String::New("Array length must be a number."));
   }
   if (length > static_cast<size_t>(kMaxLength)) {
     return ThrowException(String::New("Array length exceeds maximum length."));

test/mjsunit/external-array.js

@@ -81,6 +81,19 @@ assertEquals(2.5, get(array, 0));
 assertEquals(3.5, get(array, 1));
 }
 
+// Test non-number parameters.
+var array_with_length_from_non_number = new Int32Array("2");
+assertEquals(2, array_with_length_from_non_number.length);
+array_with_length_from_non_number = new Int32Array(undefined);
+assertEquals(0, array_with_length_from_non_number.length);
+var foo = { valueOf: function() { return 3; } };
+array_with_length_from_non_number = new Int32Array(foo);
+assertEquals(3, array_with_length_from_non_number.length);
+foo = { toString: function() { return "4"; } };
+array_with_length_from_non_number = new Int32Array(foo);
+assertEquals(4, array_with_length_from_non_number.length);
+
+
 // Test loads and stores.
 types = [Array, Int8Array, Uint8Array, Int16Array, Uint16Array, Int32Array,
          Uint32Array, PixelArray, Float32Array, Float64Array];