find_start_of_next_microdesc(const char *s, const char *eos)
{
  int started_with_annotations;
  s = eat_whitespace_eos(s, eos);
  if (!s)
    return NULL;

#define CHECK_LENGTH() STMT_BEGIN \
    if (s+32 > eos)               \
      return NULL;                \
  STMT_END

#define NEXT_LINE() STMT_BEGIN            \
    s = memchr(s, '\n', eos-s);           \
    if (!s || s+1 >= eos)                 \
      return NULL;                        \
    s++;                                  \
  STMT_END

  CHECK_LENGTH();

  started_with_annotations = (*s == '@');

  if (started_with_annotations) {
    /* Start by advancing to the first non-annotation line. */
    while (*s == '@')
      NEXT_LINE();
  }
  CHECK_LENGTH();

  /* Now we should be pointed at an onion-key line.  If we are, then skip
   * it. */
  if (!strcmpstart(s, "onion-key"))
    NEXT_LINE();

  /* Okay, now we're pointed at the first line of the microdescriptor which is
     not an annotation or onion-key.  The next line that _is_ an annotation or
     onion-key is the start of the next microdescriptor. */
  while (s+32 < eos) {
    if (*s == '@' || !strcmpstart(s, "onion-key"))
      return s;
    NEXT_LINE();
  }
  return NULL;

#undef CHECK_LENGTH
#undef NEXT_LINE
}
find_start_of_next_microdesc(const char *s, const char *eos)
{
  int started_with_annotations;
  s = eat_whitespace_eos(s, eos);
  if (!s)
    return NULL;

#define CHECK_LENGTH() STMT_BEGIN \
    if (s+32 > eos)               \
      return NULL;                \
  STMT_END

#define NEXT_LINE() STMT_BEGIN            \
    s = memchr(s, '\n', eos-s);           \
    if (!s || s+1 >= eos)                 \
      return NULL;                        \
    s++;                                  \
  STMT_END

  CHECK_LENGTH();

  started_with_annotations = (*s == '@');

  if (started_with_annotations) {
     
    while (*s == '@')
      NEXT_LINE();
  }
  CHECK_LENGTH();

   
  if (!strcmpstart(s, "onion-key"))
    NEXT_LINE();

   
  while (s+32 < eos) {
    if (*s == '@' || !strcmpstart(s, "onion-key"))
      return s;
    NEXT_LINE();
  }
  return NULL;

#undef CHECK_LENGTH
#undef NEXT_LINE
}