>I haven't had time to check, but I suspect -1 is what it's giving.
>I disagree with your reading of the standard though: -1 means failure,
>and in a failure case there is not any specification about what went
>into the buffer.
I agree with that ... but why is it failing? If the only reason it's
failing is because the buffer isn't big enough, that is wrong; it's
supposed to return the number of bytes it wanted to write. My reading
of the code we have now is that it's correctly rejecting the case where
snprintf() returns -1.