hostnameToUnicode
Converts @hostname to its canonical presentation form; a UTF-8 string in Unicode normalization form C, containing no uppercase letters, no forbidden characters, and no ASCII-encoded segments, and not ending with a trailing dot.
Of course if @hostname is not an internationalized hostname, then the canonical presentation form will be entirely ASCII.
Return
a UTF-8 hostname, which must be freed, or null if @hostname is in some way invalid.
Since
2.22
Parameters
hostname
a valid UTF-8 or ASCII hostname