WiFi.disconnect() should not reset static IP. config(0) should.

Author: JAndrassy

ArduinoNetAPIDev.md

@@ -162,6 +162,8 @@ TODO
 
 Method [`disconnect`](https://www.arduino.cc/reference/en/libraries/wifi/wifi.disconnect/) in WiFi libraries leaves the WiFi network.
 
+`disconnect()` should not clear static IP settings. Next `begin` should use the same static IP configuration if `config` was not used to change or clear static IP.
+
 ### setHostname (DHCP)
 
 Method [`setHostname`](https://www.arduino.cc/reference/en/libraries/wifinina/wifi.sethostname/) provides a way to set the hostname sent with the DHCP request. In some WiFi libraries this name is used for the locally started AP too.
@@ -182,6 +184,8 @@ config(IPAddress local_ip, IPAddress dns_server = IP_ALL_ZERO, IPAddress gateway
 
 For static IP configuration user must specify the local IP address. The rest of the settings is optional and the library will use default values: DNS and gateway as .1 IP address in the same network and net mask 255.255.255.0. 
 
+`WiFi.config(INADDR_NONE)` should clear static IP configuration and set use of DHCP on next 'begin'.
+
 For unifying the API, Ethernet libraries should use `config` too.
 
 ### setDNS (optional)

ArduinoNetLibsTestReport.md

@@ -35,7 +35,6 @@ pull requests:
 With listed pull request applied, remaining issues are
 
 * WiFi.h doesn't include WiFiClient.h
-* after using static IP, DHCP is not possible. The problem in the ESP32 WiFi library used in the firmware ([PR](https://github.com/espressif/arduino-esp32/pull/8848)).
 * hostname is not sent with DHCP request
 
 pull requests:
@@ -45,7 +44,10 @@ pull requests:
 
 ### WiFiEspAT
 
-As the WiFiEspAT library is maintained by the author of this document, all problems discovered with the tests were solved. Only issue is the reversed macAddress and BSSID for compatibility with Arduino WiFi libraries.
+Issues:
+
+* WiFi.disconnect() clears static IP
+* reversed macAddress and BSSID for compatibility with Arduino WiFi libraries.
 
 
 ## Ethernet
@@ -154,10 +156,11 @@ With listed pull requests applied, remaining issues are
 * hostname is not sent with DHCP request
 * doesn't have WiFi.h
 * does scan in `begin` and only joins the network if it is in the scan result
+* static IP change ignored after first `begin`
 
 pull requests:
 
-* [`config` ignored](https://github.com/arduino/ArduinoCore-renesas/pull/179)
+* [can't set static IP](https://github.com/arduino/ArduinoCore-renesas/pull/179)
 * [reversed MAC](https://github.com/arduino/ArduinoCore-renesas/pull/184)
 
 ### C33 Ethernet