**    forks           Show only forks and their children
**    cherrypicks     Show all cherrypicks
**    ym=YYYY-MM      Show only events for the given year/month
**    yw=YYYY-WW      Show only events for the given week of the given year
**    yw=YYYY-MM-DD   Show events for the week that includes the given day
**    ymd=YYYY-MM-DD  Show only events on the given day. The use "ymd=now"
**                    to see all changes for the current week.
**    year=YYYY       Show only events on the given year. The use "year=0"
**                    to see all changes for the current year.
**    days=N          Show events over the previous N days
**    datefmt=N       Override the date format:  0=HH:MM, 1=HH:MM:SS,
**                    2=YYYY-MM-DD HH:MM:SS, 3=YYMMDD HH:MM, and 4 means "off".
**    bisect          Show the check-ins that are in the current bisect
**    showid          Show RIDs
**    showsql         Show the SQL text
**
** p= and d= can appear individually or together.  If either p= or d=
** appear, then u=, y=, a=, and b= are ignored.
**
** If both a= and b= appear then both upper and lower bounds are honored.
**
** When multiple time-related filters are used, e.g. ym, yw, and ymd,
** which one(s) is/are applied is unspecified and may change between
** fossil versions.
**
** CHECKIN or TIMEORTAG can be a check-in hash prefix, or a tag, or the
** name of a branch.
*/
void page_timeline(void){
  Stmt q;                            /* Query used to generate the timeline */
  Blob sql;                          /* text of SQL used to generate timeline */

  const char *zTagSql = 0;           /* Tag/branch match SQL expression */
  const char *zSearch = P("s");      /* Search string */
  const char *zUses = P("uf");       /* Only show check-ins hold this file */
  const char *zYearMonth = P("ym");  /* Show check-ins for the given YYYY-MM */
  const char *zYearWeek = P("yw");   /* Check-ins for YYYY-WW (week-of-year) */
  char *zYearWeekStart = 0;          /* YYYY-MM-DD for start of YYYY-WW */
  const char *zDay = P("ymd");       /* Check-ins for the day YYYY-MM-DD */
  const char *zYear = P("year");     /* Events for the year YYYY */
  const char *zNDays = P("days");    /* Show events over the previous N days */
  int nDays = 0;                     /* Numeric value for zNDays */
  const char *zChng = P("chng");     /* List of GLOBs for files that changed */
  int useDividers = P("nd")==0;      /* Show dividers if "nd" is missing */
  int renameOnly = P("namechng")!=0; /* Show only check-ins that rename files */
  int forkOnly = PB("forks");        /* Show only forks and their children */
  int bisectLocal = PB("bisect");    /* Show the check-ins of the bisect */

    }
    else if( zNDays ){
      nDays = atoi(zNDays);
      if( nDays<1 ) nDays = 1;
      blob_append_sql(&cond, " AND event.mtime>=julianday('now','-%d days') ",
                      nDays);
      nEntry = -1;
    }
    else if( zYear &&
             ((4==strlen(zYear) && atoi(zYear)>1900)
              || (1==strlen(zYear) && 0==atoi(zYear)))){
      int year = atoi(zYear);
      char *zNext = 0;
      if(0==year){/*use current year*/
        Stmt qy;
        db_prepare(&qy, "SELECT strftime('%%Y','now')");
        db_step(&qy);
        year = db_column_int(&qy, 0);
        zYear = fossil_strdup(db_column_text(&qy, 0));
        db_finalize(&qy);
      }else{
        zNext = mprintf("%d", year+1);
        if( db_int(0,
          "SELECT EXISTS (SELECT 1 FROM event CROSS JOIN blob"
          " WHERE blob.rid=event.objid AND strftime('%%Y',mtime)=%Q %s)",
          zNext, blob_sql_text(&cond))
        ){
          zNewerButton = fossil_strdup(url_render(&url, "year", zNext, 0, 0));
          zNewerButtonLabel = "Following year";
        }
        fossil_free(zNext);
      }
      zNext = mprintf("%d", year-1);
      if( db_int(0,
          "SELECT EXISTS (SELECT 1 FROM event CROSS JOIN blob"
          " WHERE blob.rid=event.objid AND strftime('%%Y',mtime)=%Q %s)",
          zNext, blob_sql_text(&cond))
      ){
        zOlderButton = fossil_strdup(url_render(&url, "year", zNext, 0, 0));
        zOlderButtonLabel = "Previous year";
      }
      fossil_free(zNext);
      blob_append_sql(&cond, " AND %Q=strftime('%%Y',event.mtime) ",
                      zYear);
      nEntry = -1;
    }
    if( zTagSql ){
      db_multi_exec(
        "CREATE TEMP TABLE selected_nodes(rid INTEGER PRIMARY KEY);"
        "INSERT OR IGNORE INTO selected_nodes"
        " SELECT tagxref.rid FROM tagxref NATURAL JOIN tag"
        " WHERE %s AND tagtype>0", zTagSql/*safe-for-%s*/