Fossil

  if( bVerifyNotAHash ){
    if( db_exists("SELECT 1 FROM blob WHERE uuid GLOB '%q*'",zIn) ) return 0;
  }

  /* It looks like this may be a date.  Return it with punctuation added. */
  return zEDate;
}

/*
** The data-time string in the argument is going to be used as an
** upper bound like this:    mtime<=julianday(zDate,'localtime').
** But if the zDate parameter omits the fractional seconds or the
** seconds, or the time, that might mess up the == part of the
** comparison.  So add in missing factional seconds or seconds or time.
**
** The returned string is held in a static buffer that is overwritten
** with each call, or else is just a copy of its input if there are
** no changes.
*/
const char *fossil_roundup_date(const char *zDate){
  static char zUp[24];
  int n = (int)strlen(zDate);
  if( n==19 ){  /* YYYY-MM-DD HH:MM:SS */
    memcpy(zUp, zDate, 19);
    memcpy(zUp+19, ".999", 5);
    return zUp;
  }
  if( n==16 ){ /* YYYY-MM-DD HH:MM */
    memcpy(zUp, zDate, 16);
    memcpy(zUp+16, ":59.999", 8);
    return zUp;
  }
  if( n==10 ){ /* YYYY-MM-DD */
    memcpy(zUp, zDate, 10);
    memcpy(zUp+10, " 23:59:59.999", 14);
    return zUp;
  }
  return zDate;
}


/*
** Return the RID that is the "root" of the branch that contains
** check-in "rid".  Details depending on eType:
**
**    eType==0    The check-in of the parent branch off of which
**                the branch containing RID originally diverged.

  if( memcmp(zTag, "date:", 5)==0 ){
    zDate = fossil_expand_datetime(&zTag[5],0);
    if( zDate==0 ) zDate = &zTag[5];
    rid = db_int(0,
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q,fromLocal()) AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      fossil_roundup_date(zDate), zType);
    return rid;
  }
  if( fossil_isdate(zTag) ){
    rid = db_int(0,
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q,fromLocal()) AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      fossil_roundup_date(zTag), zType);
    if( rid) return rid;
  }

  /* Deprecated date & time formats:   "local:" + date-time and
  ** "utc:" + date-time */
  if( memcmp(zTag, "local:", 6)==0 ){
    rid = db_int(0,
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q) AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      &zTag[6], zType);
    return rid;
  }
  if( memcmp(zTag, "utc:", 4)==0 ){
    rid = db_int(0,
      "SELECT objid FROM event"
      " WHERE mtime<=julianday('%qz') AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      fossil_roundup_date(&zTag[4]), zType);
    return rid;
  }

  /* "tag:" + symbolic-name */
  if( memcmp(zTag, "tag:", 4)==0 ){
    rid = db_int(0,
       "SELECT event.objid, max(event.mtime)"

  if( strncmp(zTag, "merge-in:", 9)==0 ){
    rid = symbolic_name_to_rid(zTag+9, zType);
    return start_of_branch(rid, 2);
  }

  /* symbolic-name ":" date-time */
  nTag = strlen(zTag);
  for(i=0; i<nTag-8 && zTag[i]!=':'; i++){}
  if( zTag[i]==':' 
   && (fossil_isdate(&zTag[i+1]) || fossil_expand_datetime(&zTag[i+1],0)!=0)
  ){
    char *zDate = mprintf("%s", &zTag[i+1]);
    char *zTagBase = mprintf("%.*s", i, zTag);
    char *zXDate;
    int nDate = strlen(zDate);
    if( sqlite3_strnicmp(&zDate[nDate-3],"utc",3)==0 ){
      zDate[nDate-3] = 'z';
      zDate[nDate-2] = 0;
    }
    zXDate = fossil_expand_datetime(zDate,0);
    if( zXDate==0 ) zXDate = zDate;
    rid = db_int(0,
      "SELECT event.objid, max(event.mtime)"
      "  FROM tag, tagxref, event"
      " WHERE tag.tagname='sym-%q' "
      "   AND tagxref.tagid=tag.tagid AND tagxref.tagtype>0 "
      "   AND event.objid=tagxref.rid "
      "   AND event.mtime<=julianday(%Q,fromLocal())"
      "   AND event.type GLOB '%q'",
      zTagBase, fossil_roundup_date(zXDate), zType
    );
    fossil_free(zDate);
    fossil_free(zTagBase);
    return rid;
  }

  /* Remove optional [...] */
  zXTag = zTag;
  nXTag = nTag;
  if( zXTag[0]=='[' ){

  /* Pure numeric date/time */
  zDate = fossil_expand_datetime(zTag, 0);
  if( zDate ){
    rid = db_int(0,
      "SELECT objid FROM event"
      " WHERE mtime<=julianday(%Q,fromLocal()) AND type GLOB '%q'"
      " ORDER BY mtime DESC LIMIT 1",
      fossil_roundup_date(zDate), zType);
    if( rid) return rid;
  }


  /* Undocumented:  numeric tags get translated directly into the RID */
  if( memcmp(zTag, "rid:", 4)==0 ){
    zTag += 4;

  const char *zDate;
  if( z==0 ) return -1.0;
  if( fossil_isdate(z) ){
    mtime = db_double(0.0, "SELECT julianday(%Q,fromLocal())", z);
    if( mtime>0.0 ) return mtime;
  }
  zDate = fossil_expand_datetime(z, 1);
  if( zDate!=0 ){
    mtime = db_double(0.0, "SELECT julianday(%Q,fromLocal())",
                      fossil_roundup_date(zDate));
    if( mtime>0.0 ){
      if( pzDisplay ) *pzDisplay = fossil_strdup(zDate);
      return mtime;
    }
  }
  rid = symbolic_name_to_rid(z, "*");
  if( rid ){
    mtime = db_double(0.0, "SELECT mtime FROM event WHERE objid=%d", rid);
  }else{
    mtime = db_double(-1.0,
        "SELECT max(event.mtime) FROM event, tag, tagxref"