Return false in TryNumberToSize if there is a cast error

test/cctest/test-conversions.cc

 // Copyright 2011 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 426 matching lines @@
       CHECK_EQ(result, 2u);
     }
     Handle<HeapNumber> heap_number2 = isolate->factory()->NewHeapNumber(
         static_cast<double>(std::numeric_limits<size_t>::max()) + 10000.0);
     {
       SealHandleScope no_handles(isolate);
       CHECK(!TryNumberToSize(*heap_number2, &result));
     }
   }
 }
+
+TEST(CastErrorInTryNumberToSize) {
+  i::Isolate* isolate = CcTest::i_isolate();
+  UnicodeCache uc;
+  size_t result = 0;
+  {
+    HandleScope scope(isolate);
+    double value = StringToDouble(&uc, "0x10000000000000000",

[ahaas, 2016/12/07 16:20:38]

I think you could just write 
double value = 18446744073709551616.0;
which is 0x10000000000000000. Please add a comment for that, because I think
this is not obvious to see.

[qiuyi.zqy, 2016/12/07 18:13:36]

Done.

+                                  ALLOW_HEX | ALLOW_IMPLICIT_OCTAL);
+    Handle<HeapNumber> heap_number = isolate->factory()->NewHeapNumber(value);
+    bool success = TryNumberToSize(*heap_number, &result);
+    if (success && value > 0) {

[ahaas, 2016/12/07 16:20:38]

I think you could just write "CHECK(!success);" instead of this if-block.

[qiuyi.zqy, 2016/12/07 18:13:36]

Done.

+      CHECK(result != 0);
+    }
+  }
+}