From 4c0bbea95328b43f1b18cd687709ef72d998058b Mon Sep 17 00:00:00 2001
From: maidnl <d.aimo@arduino.cc>
Date: Mon, 17 Jun 2024 10:05:00 +0200
Subject: [PATCH] properly initialized and checked Ethernet init callback

---
 libraries/Ethernet/src/Ethernet.cpp | 5 ++++-
 libraries/Ethernet/src/Ethernet.h   | 2 +-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/libraries/Ethernet/src/Ethernet.cpp b/libraries/Ethernet/src/Ethernet.cpp
index 2e0f1a94f..ef07889c3 100644
--- a/libraries/Ethernet/src/Ethernet.cpp
+++ b/libraries/Ethernet/src/Ethernet.cpp
@@ -5,7 +5,10 @@
 int arduino::EthernetClass::begin(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout) {
   if (eth_if == nullptr) {
     //Q: What is the callback for?
-    _initializerCallback();
+    //A: To call a specific function on your system before any initialization is performed
+    if(_initializerCallback != nullptr) {
+      _initializerCallback();
+    }
     if (eth_if == nullptr) return 0;
   }
   eth_if->set_dhcp(true);
diff --git a/libraries/Ethernet/src/Ethernet.h b/libraries/Ethernet/src/Ethernet.h
index 2fc2ef240..f27a46fc0 100644
--- a/libraries/Ethernet/src/Ethernet.h
+++ b/libraries/Ethernet/src/Ethernet.h
@@ -121,7 +121,7 @@ class EthernetClass : public MbedSocketClass {
   volatile EthernetLinkStatus _currentNetworkStatus = Unknown;
   EthernetInterface net;
   EthernetInterface *eth_if = &net;
-  voidPrtFuncPtr _initializerCallback;
+  voidPrtFuncPtr _initializerCallback = nullptr;
   arduino::IPAddress ipAddressFromSocketAddress(SocketAddress socketAddress);
 };