Change e212 dissector mcc/mnc to string
Summary
All of the e212 mcc/mncs filters, are parsed out as integers: https://www.wireshark.org/docs/dfref/e/e212.html
They should be strings because of the nature of MNC being either 2 digit or 3 digit and many carriers MNC start with a 0.
Take a look at mcc_mnc_3digits_codes[] in packet-e212.c, and you can clearly see many of the MNCs start with 0 (search for MCC 334 for example).
What is the current bug behavior?
As an example, currently tshark with -e fields will return MNC as 20 (when it should be 020), but Wireshark's details screen shows 020 because it keeps it in string from. Information is lost to tshark/filters because the filter stores it as an integer.
Using Wirehsark filters also has the same problem: "e212.mnc == 020" does not work, but "e212.mnc == 20" does, even though the MNC is actually 020.
What is the expected correct behavior?
Both Wireshark and tshark filters should preserve the MCC and MNC as strings, thus preserving the leading 0s.
I have over 10 years experience in the telecom industry. I've learned to always store them as strings.