Buffer with valid ASCII characters classified as non UTF-8

[sovereignstack]

NULL terminated strings (NULL is part of the buffer) should qualify as UTF-8 but don't.
In fact only a few characters below 0x20 qualify as valid.

The check for ASCII should simply be
if(bytes[i]<=0x7F)

And not

        if(     (// ASCII
                    bytes[i] == 0x09 ||
                    bytes[i] == 0x0A ||
                    bytes[i] == 0x0D ||
                    (0x20 <= bytes[i] && bytes[i] <= 0x7E)
                )

UTF-8 is supposed to be backward compatible with ASCII.

UTF-8 Wiki

The salient features of this scheme are as follows:

Backward compatibility: One-byte codes are used only for the ASCII values 0 through 127. In this case the UTF-8 code has the same value as the ASCII code. The high-order bit of these codes is always 0. This means that ASCII text is valid UTF-8....

The string is sent by a device and is received by a third party software (node-red) which uses is-UTF8. I can't change either.

[ilkkao]

I'd like to see ASCII control characters to be considered valid UTF-8 as well.

[bkdotcom]

looks like this code was based on the regex found at https://www.w3.org/International/questions/qa-forms-utf-8

I opened an issue re the w3.org regex:
w3c/i18n-drafts#90

[ilkkao]

I btw switched to https://github.com/websockets/utf-8-validate that allows all ASCII characters