Make ESPmDNS compatible to ESP8266mDNS

[beegee-tokyo]

The ESP8266 version of the mDNS library expected service name and protocol without leading _ (underscore). The ESP32 version expected service name and protocol with leading _ (underscore).

This small change makes the ESP32 version compatible with the ESP8266 version and keeps backward compatibility with existing code by accepting service name and protocol either with or without leading _ (underscore).

See issues #962 #387

Tested with following combinations:

 MDNS.addService("test1","tcp",9998); MDNS.addServiceTxt("test1", "tcp", "id", "mDNS-Test"); MDNS.addService("_test2","tcp",9998); MDNS.addServiceTxt("_test2", "tcp", "id", "mDNS-Test"); MDNS.addService("test3","_tcp",9998); MDNS.addServiceTxt("test3", "_tcp", "id", "mDNS-Test"); MDNS.addService("_test4","_tcp",9998); MDNS.addServiceTxt("_test4", "_tcp", "id", "mDNS-Test");

[baggior]

thank you

when will be merged?

[atanisoft]

shouldn't this be merged with the line above as:
_hostname = hostName.toLowerCase();

[baggior]

I don't think
String.toLowerCase() make side effect on the object itself and doesn't returns anything
https://www.arduino.cc/reference/en/language/variables/data-types/string/functions/tolowercase/

[atanisoft]

You are right, I was looking at it and it looked odd. Normally a method like this would return the modification rather than do the modification on the object itself. It appears that https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/WString.h#L255 is just doing a direct modification on the object in place.

[beegee-tokyo]

@me-no-dev - Anybody working on these pull requests? There are 27 open pull requests, and it seems nobody is working on them.

[baggior]

@me-no-dev
How can I contribute working on the pull requests?

What do I have to do to commit on this repository?

[me-no-dev]

Sorry guys, I had lots of unrelated to Arduino work to cover :) I surely am back though