Fossil

  rid = db_int(0, "SELECT pid FROM plink AS x WHERE NOT EXISTS("
                  "  SELECT 1 FROM plink WHERE cid=x.pid)");
  if( rid==0 ) return;

  /* Add the trunk tag to the root of the whole tree */
  zUuid = db_text(0, "SELECT uuid FROM blob WHERE rid=%d", rid);
  if( zUuid==0 ) return;
  tag_add_artifact("sym-", "trunk", zUuid, 0, 2, 0, 0);
  tag_add_artifact("", "branch", zUuid, "trunk", 2, 0, 0);
}

/*
** Core function to rebuild the infomration in the derived tables of a
** fossil repository from the blobs. This function is shared between
** 'rebuild_database' ('rebuild') and 'reconstruct_cmd'
** ('reconstruct'), both of which have to regenerate this information

** or cancels a tag.
*/
void tag_add_artifact(
  const char *zPrefix,        /* Prefix to prepend to tag name */
  const char *zTagname,       /* The tag to add or cancel */
  const char *zObjName,       /* Name of object attached to */
  const char *zValue,         /* Value for the tag.  Might be NULL */
  int tagtype,                /* 0:cancel 1:singleton 2:propagated */
  const char *zDateOvrd,      /* Override date string */
  const char *zUserOvrd       /* Override user name */
){
  int rid;
  int nrid;
  char *zDate;
  Blob uuid;
  Blob ctrl;
  Blob cksum;

    fossil_fatal(
       "invalid tag name \"%s\" - might be confused with"
       " a hexadecimal artifact ID",
       zTagname
    );
  }
#endif
  zDate = date_in_standard_format(zDateOvrd ? zDateOvrd : "now");
  zDate[10] = 'T';
  blob_appendf(&ctrl, "D %s\n", zDate);
  blob_appendf(&ctrl, "T %c%s%F %b",
               zTagtype[tagtype], zPrefix, zTagname, &uuid);
  if( tagtype>0 && zValue && zValue[0] ){
    blob_appendf(&ctrl, " %F\n", zValue);
  }else{
    blob_appendf(&ctrl, "\n");
  }
  blob_appendf(&ctrl, "U %F\n", zUserOvrd ? zUserOvrd : g.zLogin);
  md5sum_blob(&ctrl, &cksum);
  blob_appendf(&ctrl, "Z %b\n", &cksum);
  nrid = content_put(&ctrl, 0, 0);
  manifest_crosslink(nrid, &ctrl);
}

/*

** will be taken as an artifact or baseline ID and fossil will
** probably complain that no such revision was found. However
**
**   fossil update tag:decaf
**
** will assume that "decaf" is a tag/branch name.
**
** only allow --date-override and --user-override in 
**   %fossil tag add --date-override 'YYYY-MMM-DD HH:MM:SS' \
**                   --user-override user 
** in order to import history from other scm systems
*/
void tag_cmd(void){
  int n;
  int fRaw = find_option("raw","",0)!=0;
  int fPropagate = find_option("propagate","",0)!=0;
  const char *zPrefix = fRaw ? "" : "sym-";

  db_find_and_open_repository(1);
  if( g.argc<3 ){
    goto tag_cmd_usage;
  }
  n = strlen(g.argv[2]);
  if( n==0 ){
    goto tag_cmd_usage;
  }

  if( strncmp(g.argv[2],"add",n)==0 ){
    char *zValue;
    const char *zDateOvrd = find_option("date-override",0,1);
    const char *zUserOvrd = find_option("user-override",0,1);
    if( g.argc!=5 && g.argc!=6 ){
      usage("add ?--raw? ?--propagate? TAGNAME CHECK-IN ?VALUE?");
    }
    zValue = g.argc==6 ? g.argv[5] : 0;
    db_begin_transaction();
    tag_add_artifact(zPrefix, g.argv[3], g.argv[4], zValue,
                     1+fPropagate,zDateOvrd,zUserOvrd);
    db_end_transaction(0);
  }else

  if( strncmp(g.argv[2],"branch",n)==0 ){
    fossil_fatal("the \"fossil tag branch\" command is discontinued\n"
                 "Use the \"fossil branch new\" command instead.");
  }else

  if( strncmp(g.argv[2],"cancel",n)==0 ){
    if( g.argc!=5 ){
      usage("cancel ?--raw? TAGNAME CHECK-IN");
    }
    db_begin_transaction();
    tag_add_artifact(zPrefix, g.argv[3], g.argv[4], 0, 0, 0, 0);
    db_end_transaction(0);
  }else

  if( strncmp(g.argv[2],"find",n)==0 ){
    Stmt q;
    if( g.argc!=4 ){
      usage("find ?--raw? TAGNAME");