** See also the "update" command.
*/
void checkout_cmd(void){
  int forceFlag;                 /* Force checkout even if edits exist */
  int keepFlag;                  /* Do not change any files on disk */
  int latestFlag;                /* Checkout the latest version */
  char *zVers;                   /* Version to checkout */
  int promptFlag;                /* True to prompt before overwriting */
  int vid, prior;
  Blob cksum1, cksum1b, cksum2;
  
  db_must_be_within_tree();
  db_begin_transaction();
  forceFlag = find_option("force","f",0)!=0;
  keepFlag = find_option("keep",0,0)!=0;
  latestFlag = find_option("latest",0,0)!=0;
  promptFlag = find_option("prompt",0,0)!=0;  /* Prompt user before overwrite */
  if( (latestFlag!=0 && g.argc!=2) || (latestFlag==0 && g.argc!=3) ){
     usage("VERSION|--latest ?--force? ?--keep?");
  }
  if( !forceFlag && unsaved_changes()==1 ){
    fossil_fatal("there are unsaved changes in the current checkout");
  }
  if( forceFlag ){

    return;
  }
  if( !keepFlag ){
    uncheckout(prior);
  }
  db_multi_exec("DELETE FROM vfile WHERE vid!=%d", vid);
  if( !keepFlag ){
    vfile_to_disk(vid, 0, 1, promptFlag);
  }
  manifest_to_disk(vid);
  db_lset_int("checkout", vid);
  undo_reset();
  db_multi_exec("DELETE FROM vmerge");
  if( !keepFlag ){
    vfile_aggregate_checksum_manifest(vid, &cksum1, &cksum1b);