another fix since xmr hardfork version increased

src/main.cc

@@ -195,6 +195,38 @@ void construct_block_blob(const Nan::FunctionCallbackInfo<v8::Value>& info) {
     blobdata block_template_blob = std::string(Buffer::Data(block_template_buf), Buffer::Length(block_template_buf));
     blobdata output = "";
 
+    block b = AUTO_VAL_INIT(b);
+    if (!parse_and_validate_block_from_blob(block_template_blob, b))
+        return THROW_ERROR_EXCEPTION("Failed to parse block");
+
+    if (!block_to_blob(b, output))
+        return THROW_ERROR_EXCEPTION("Failed to convert block to blob");
+
+    v8::Local<v8::Value> returnValue = Nan::CopyBuffer((char*)output.data(), output.size()).ToLocalChecked();
+    info.GetReturnValue().Set(
+        returnValue
+    );
+}
+
+void construct_block_blob_fa(const Nan::FunctionCallbackInfo<v8::Value>& info) {
+
+    if (info.Length() < 2)
+        return THROW_ERROR_EXCEPTION("You must provide two arguments.");
+
+    Local<Object> block_template_buf = info[0]->ToObject();
+    Local<Object> nonce_buf = info[1]->ToObject();
+
+    if (!Buffer::HasInstance(block_template_buf) || !Buffer::HasInstance(nonce_buf))
+        return THROW_ERROR_EXCEPTION("Both arguments should be buffer objects.");
+
+    if (Buffer::Length(nonce_buf) != 4)
+        return THROW_ERROR_EXCEPTION("Nonce buffer has invalid size.");
+
+    uint32_t nonce = *reinterpret_cast<uint32_t*>(Buffer::Data(nonce_buf));
+
+    blobdata block_template_blob = std::string(Buffer::Data(block_template_buf), Buffer::Length(block_template_buf));
+    blobdata output = "";
+
     block b = AUTO_VAL_INIT(b);
     if (!parse_and_validate_block_from_blob(block_template_blob, b))
         return THROW_ERROR_EXCEPTION("Failed to parse block");