From 62cce64e562bda1ede2bb1064c3b44b35c3c4658 Mon Sep 17 00:00:00 2001
From: Matt Witherspoon <32485495+spoonincode@users.noreply.github.com>
Date: Mon, 18 Sep 2023 14:33:06 -0400
Subject: [PATCH] avoid possible memcpy with nullptr when action data size is 0

---
 libraries/chain/webassembly/action.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libraries/chain/webassembly/action.cpp b/libraries/chain/webassembly/action.cpp
index 307ddafe6b..fa8bc58981 100644
--- a/libraries/chain/webassembly/action.cpp
+++ b/libraries/chain/webassembly/action.cpp
@@ -5,6 +5,7 @@
 namespace eosio { namespace chain { namespace webassembly {
    int32_t interface::read_action_data(legacy_span<char> memory) const {
       auto s = context.get_action().data.size();
+      if( s == 0 ) return s;
       if( memory.size() == 0 ) return s;
 
       auto copy_size = std::min( static_cast<size_t>(memory.size()), s );