Handle null-terminated MFG_ strings

[puddly]

Backups were being created with invalid metadata:

"ezsp": {
    "manufacturer": "Nabu Casa\u0000",
    "board": "SkyBlue v0.1\u0000",
    "version": "7.1.0.0 build 191",
    "stack_version": 9,
    "can_write_custom_eui64": false
}

[MattWestb]

The manufacture and board name token is normal terminated with one space.
But if writing one long string you is getting one warning (from Commander) that is no space between the token but its being written OK in the device flash.

Example for 15 charter long token that is not generating error (16 do but working OK in ZHA):
MW-Marcus-RNP.txt

[puddly]

These tokens seem to be 16 bytes long. Maybe Commander adds \x00 at the end to terminate the string, which means that you will have only 15 characters to work with.

Both should work with bellows but I think the \x00 at the end is the "correct" way.

[MattWestb]

I think the same that commander adding the \x00 for strings that is under 16 chaster but i thing the flash is not having it then using 16 chaster tokens so dont make it braking if its not coming on stop charter 👍

Great work as normal from you Puddly !!!

PS: My old Billy token was 16 charters then using EZSP and now NCP or RCP and it was working OK in ZHA only warning then flashing the tokens.

[Adminiuga]

LGTM

[anbugge]

Your assumptions are correct :)

This was actually a change in Commander a few years ago. From the change log:

• The MFG string tokens "MFG_STRING" and "MFG_BOARD_NAME" will now be zero terminated when written by Commander
  • Previously the string was unterminated, and unused token space is filled with 0xFF
  • If the string is exactly 16 bytes, filling the token, a warning will be raised and the string will be unterminated