[AngryParsley]

It's a very rare situation in which truncation is worse than a buffer overflow. I'd also bet that erasing the destination string is more liable to cause problems than truncating it. For example, the programmer might have pointers to locations in the destination string passed to str*cat. All of a sudden, these pointers are to garbage data.

strlcpy's behavior is the same as snprintf: return what the length would have been if there was enough room. That way one can recover from the error and realloc enough space. C programmers are used to this pattern.