That was precisely my point, that the null byte is not ignored like the other characters after it. It's part of the data when encoded in the format "null-terminated string", but not part of the value. It doesn't appear in the output value because it's a format detail, the same way the byte order doesn't appear after decoding a little endian or big endian integer value.

But that's nitpicking, this would make the documentation misleading rather than plain wrong, which should also be avoided in a documentation. I think your phrasing returns everything up to but not including the first null. is fine.