const char *zMode;
  const char *zCur;

  if( g.zBaseURL!=0 ) return;
  if( zAltBase ){
    int i, n, c;
    g.zTop = g.zBaseURL = mprintf("%s", zAltBase);
    if( memcmp(g.zTop, "http://", 7)==0 ){
    if( strncmp(g.zTop, "http://", 7)==0 ){
      /* it is HTTP, replace prefix with HTTPS. */
      g.zHttpsURL = mprintf("https://%s", &g.zTop[7]);
    }else if( memcmp(g.zTop,"https://",8)==0 ){
    }else if( strncmp(g.zTop, "https://", 8)==0 ){
      /* it is already HTTPS, use it. */
      g.zHttpsURL = mprintf("%s", g.zTop);
    }else{
      fossil_fatal("argument to --baseurl should be 'http://host/path'"
                   " or 'https://host/path'");
    }
    for(i=n=0; (c = g.zTop[i])!=0; i++){