[api] Relax CHECK for ArrayBuffer API abuse

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 6542 matching lines @@
       i_isolate->factory()->NewJSArrayBuffer(i::SharedFlag::kNotShared);
   i::Runtime::SetupArrayBufferAllocatingData(i_isolate, obj, byte_length);
   return Utils::ToLocal(obj);
 }
 
 
 Local<ArrayBuffer> v8::ArrayBuffer::New(Isolate* isolate, void* data,
                                         size_t byte_length,
                                         ArrayBufferCreationMode mode) {
   // Embedders must guarantee that the external backing store is valid.
-  CHECK(data != NULL);
+  CHECK(byte_length == 0 || data != NULL);
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, "v8::ArrayBuffer::New(void*, size_t)");
   ENTER_V8(i_isolate);
   i::Handle<i::JSArrayBuffer> obj =
       i_isolate->factory()->NewJSArrayBuffer(i::SharedFlag::kNotShared);
   i::Runtime::SetupArrayBuffer(i_isolate, obj,
                                mode == ArrayBufferCreationMode::kExternalized,
                                data, byte_length);
   return Utils::ToLocal(obj);
 }
@@ skipping 178 matching lines @@
                                              i::SharedFlag::kShared);
   return Utils::ToLocalShared(obj);
 }
 
 
 Local<SharedArrayBuffer> v8::SharedArrayBuffer::New(
     Isolate* isolate, void* data, size_t byte_length,
     ArrayBufferCreationMode mode) {
   CHECK(i::FLAG_harmony_sharedarraybuffer);
   // Embedders must guarantee that the external backing store is valid.
-  CHECK(data != NULL);
+  CHECK(byte_length == 0 || data != NULL);
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   LOG_API(i_isolate, "v8::SharedArrayBuffer::New(void*, size_t)");
   ENTER_V8(i_isolate);
   i::Handle<i::JSArrayBuffer> obj =
       i_isolate->factory()->NewJSArrayBuffer(i::SharedFlag::kShared);
   i::Runtime::SetupArrayBuffer(i_isolate, obj,
                                mode == ArrayBufferCreationMode::kExternalized,
                                data, byte_length, i::SharedFlag::kShared);
   return Utils::ToLocalShared(obj);
 }
@@ skipping 1635 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8