From 9470d33a50463c9002f513fa4e86d52758e2be8d Mon Sep 17 00:00:00 2001
From: Ayrat Badykov <ayratin555@gmail.com>
Date: Tue, 18 Jun 2019 13:08:46 +0300
Subject: [PATCH] token transfer type fixes

---
 apps/explorer/lib/explorer/chain.ex | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/apps/explorer/lib/explorer/chain.ex b/apps/explorer/lib/explorer/chain.ex
index c40c2a492b..72b907d552 100644
--- a/apps/explorer/lib/explorer/chain.ex
+++ b/apps/explorer/lib/explorer/chain.ex
@@ -2907,8 +2907,6 @@ defmodule Explorer.Chain do
       ) do
     zero_wei = %Wei{value: Decimal.new(0)}
 
-    transaction = Repo.preload(transaction, token_transfers: :token)
-
     # https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/token/ERC721/ERC721.sol#L35
     case {to_string(input), value} do
       # transferFrom(address,address,uint256)
@@ -2932,6 +2930,9 @@ defmodule Explorer.Chain do
 
         find_erc721_token_transfer(transaction.token_transfers, {from_address, to_address})
 
+      {"0xf907fc5b" <> _params, ^zero_wei} ->
+        :erc20
+
       # check for ERC 20 or for old ERC 721 token versions
       {unquote(TokenTransfer.transfer_function_signature()) <> params, ^zero_wei} ->
         types = [:address, {:uint, 256}]
@@ -2957,22 +2958,23 @@ defmodule Explorer.Chain do
         token_transfer.from_address_hash.bytes == from_address && token_transfer.to_address_hash.bytes == to_address
       end)
 
-    if token_transfer, do: {:erc721, token_transfer}
+    if token_transfer, do: :erc721
   end
 
   defp find_erc721_or_erc20_token_transfer(token_transfers, {address, decimal_value}) do
     token_transfer =
       Enum.find(token_transfers, fn token_transfer ->
-        token_transfer.to_address_hash.bytes == address &&
-          (token_transfer.amount == decimal_value || token_transfer.token_id)
+        token_transfer.to_address_hash.bytes == address && token_transfer.amount == decimal_value
       end)
 
     if token_transfer do
       case token_transfer.token do
-        %Token{type: "ERC-20"} -> {:erc20, token_transfer}
-        %Token{type: "ERC-721"} -> {:erc721, token_transfer}
+        %Token{type: "ERC-20"} -> :erc20
+        %Token{type: "ERC-721"} -> :erc721
         _ -> nil
       end
+    else
+      :erc20
     end
   end