has_trailing_escape
int has_trailing_escape(char *, char *);
if ((l = t - ibufp) < 2 || !has_trailing_escape(ibufp, ibufp + l - 1)) {
if (n < 2 || !has_trailing_escape(cvbuf, cvbuf + l - 1))
return (s == t || *(t - 1) != '\\') ? 0 : !has_trailing_escape(s, t - 1);