fix for UDP endPacket failing after an attempt to connect to an non existent WiFi network

Author: maidnl

Diff for: libraries/WiFi/src/WiFi.cpp

@@ -60,6 +60,13 @@ int arduino::WiFiClass::begin(const char* ssid, const char* passphrase, wl_enc_t
     _security = ap_list[connected_ap].get_security();
   } else {
     // For hidden networks, the security mode must be set explicitly.
+    // if ENC_TYPE_UNKNOWN this means that is the default value and so the user
+    // has not set it... no worth trying, it is probably an unknown (not hidden) 
+    // interface
+    if(security == ENC_TYPE_UNKNOWN) {
+      _currentNetworkStatus = WL_CONNECT_FAILED;
+      return _currentNetworkStatus;
+    }
     _security = enum2sec(security);
   }
 

Diff for: libraries/WiFi/src/WiFi.h

@@ -74,7 +74,7 @@ class WiFiClass : public MbedSocketClass {
      * param passphrase: Passphrase. Valid characters in a passphrase
      *        must be between ASCII 32-126 (decimal).
      */
-  int begin(const char* ssid, const char* passphrase, wl_enc_type security = ENC_TYPE_CCMP);
+  int begin(const char* ssid, const char* passphrase, wl_enc_type security = ENC_TYPE_UNKNOWN);
 
   // Inherit config methods from the parent class
   using MbedSocketClass::config;