Bugfix/wificlient (#273)

* WiFiClient - Properly initialize and check _rxBuffer

---------

Co-authored-by: Me No Dev <[email protected]>
Co-authored-by: Lucas Saavedra Vaz <[email protected]>

Author: 3 people

.github/ISSUE_TEMPLATE/Issue-report.yml

@@ -41,6 +41,8 @@ body:
       options:
         - latest master (checkout manually)
         - latest development Release Candidate (RC-X)
+        - v2.0.13
+        - v2.0.12
         - v2.0.11
         - v2.0.10
         - v2.0.9

libraries/WiFi/src/WiFiClient.cpp

@@ -187,7 +187,7 @@ class WiFiClientSocketHandle {
     }
 };
 
-WiFiClient::WiFiClient():_connected(false),_timeout(WIFI_CLIENT_DEF_CONN_TIMEOUT_MS),next(NULL)
+WiFiClient::WiFiClient():_rxBuffer(nullptr),_connected(false),_timeout(WIFI_CLIENT_DEF_CONN_TIMEOUT_MS),next(NULL)
 {
 }
 
@@ -536,7 +536,9 @@ int WiFiClient::available()
 // Though flushing means to send all pending data,
 // seems that in Arduino it also means to clear RX
 void WiFiClient::flush() {
-    _rxBuffer->flush();
+    if (_rxBuffer != nullptr) {
+        _rxBuffer->flush();
+    }
 }
 
 uint8_t WiFiClient::connected()