safe_realloc ((void **) &r, ++rlen);
safe_realloc (&r, ++rlen);
char *mutt_quote_string (const char *s){  char *r, *pr;  size_t rlen;  rlen = mutt_strlen (s) + 3;  pr = r = (char *) safe_malloc (rlen);  *pr++ = '"';  while (*s)  {    if (INVALID_CHAR (*s))    {      size_t o = pr - r;      safe_realloc ((void **) &r, ++rlen);      pr = r + o;      *pr++ = '\\';    }    *pr++ = *s++;  }  *pr++ = '"';  *pr = 0;  return (r);}