** 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);

**
** See also the "close" command.
*/
void cmd_open(void){
  Blob path;
  int vid;
  int keepFlag;
  static char *azNewArgv[] = { 0, "checkout", "--prompt", "--latest", 0, 0 };
  url_proxy_options();
  keepFlag = find_option("keep",0,0)!=0;
  if( g.argc!=3 && g.argc!=4 ){
    usage("REPOSITORY-FILENAME ?VERSION?");
  }
  if( db_open_local() ){
    fossil_panic("already within an open tree rooted at %s", g.zLocalRoot);

    db_lset_int("checkout", 1);
  }else{
    char **oldArgv = g.argv;
    int oldArgc = g.argc;
    db_lset_int("checkout", vid);
    azNewArgv[0] = g.argv[0];
    g.argv = azNewArgv;
    g.argc = 4;
    if( oldArgc==4 ){
      azNewArgv[g.argc-1] = oldArgv[3];
    }
    if( keepFlag ){
      azNewArgv[g.argc++] = "--keep";
    }
    checkout_cmd();

                "saved certificate for this host!";
    }
    prompt = mprintf("\nUnknown SSL certificate:\n\n%s\n\n%s\n"
                     "Accept certificate [a=always/y/N]? ", desc, warning);
    BIO_free(mem);

    Blob ans;

    prompt_user(prompt, &ans);
    free(prompt);
    if( blob_str(&ans)[0]!='y' && blob_str(&ans)[0]!='a' ) {
      X509_free(cert);
      ssl_set_errmsg("SSL certificate declined");
      ssl_close();
      return 1;
    }
    if( blob_str(&ans)[0]=='a' ) {
      ssl_save_certificate(cert);
    }
    blob_reset(&ans);
  }
  X509_free(cert);
  return 0;
}

/*
** Save certificate to global config.

      vid, idm
    );
    idv = db_last_insert_rowid();
    db_multi_exec("UPDATE fv SET idv=%d WHERE rowid=%d", idv, rowid);
    zName = db_column_text(&q, 2);
    printf("ADDED %s\n", zName);
    undo_save(zName);
    vfile_to_disk(0, idm, 0, 0);
  }
  db_finalize(&q);
  
  /*
  ** Find files that have changed from pid->mid but not pid->vid. 
  ** Copy the mid content over into vid.
  */

    char *zName = db_text(0, "SELECT pathname FROM vfile WHERE id=%d", idv);
    /* Copy content from idm over into idv.  Overwrite idv. */
    printf("UPDATE %s\n", zName);
    undo_save(zName);
    db_multi_exec(
      "UPDATE vfile SET mrid=%d, chnged=2 WHERE id=%d", ridm, idv
    );
    vfile_to_disk(0, idv, 0, 0);
    free(zName);
  }
  db_finalize(&q);

  /*
  ** Do a three-way merge on files that have changes pid->mid and pid->vid
  */

      ** but also exists in the target checkout.  Use the current version.
      */
      printf("CONFLICT %s\n", zName);
    }else if( idt>0 && idv==0 ){
      /* File added in the target. */
      printf("ADD %s\n", zName);
      undo_save(zName);
      if( !nochangeFlag ) vfile_to_disk(0, idt, 0, 0);
    }else if( idt>0 && idv>0 && ridt!=ridv && chnged==0 ){
      /* The file is unedited.  Change it to the target version */
      printf("UPDATE %s\n", zName);
      undo_save(zName);
      if( !nochangeFlag ) vfile_to_disk(0, idt, 0, 0);
    }else if( idt>0 && idv>0 && file_size(zFullPath)<0 ){
      /* The file missing from the local check-out. Restore it to the
      ** version that appears in the target. */
      printf("UPDATE %s\n", zName);
      undo_save(zName);
      if( !nochangeFlag ) vfile_to_disk(0, idt, 0, 0);
    }else if( idt==0 && idv>0 ){
      if( ridv==0 ){
        /* Added in current checkout.  Continue to hold the file as
        ** as an addition */
        db_multi_exec("UPDATE vfile SET vid=%d WHERE id=%d", tid, idv);
      }else if( chnged ){
        /* Edited locally but deleted from the target.  Delete it. */

  db_end_transaction(0);
}

/*
** Write all files from vid to the disk.  Or if vid==0 and id!=0
** write just the specific file where VFILE.ID=id.
*/
void vfile_to_disk(
  int vid,               /* vid to write to disk */
  int id,                /* Write this one file, if not zero */
  int verbose,           /* Output progress information */
  int promptFlag         /* Prompt user to confirm overwrites */
){
  Stmt q;
  Blob content;
  int nRepos = strlen(g.zLocalRoot);

  if( vid>0 && id==0 ){
    db_prepare(&q, "SELECT id, %Q || pathname, mrid"
                   "  FROM vfile"

  while( db_step(&q)==SQLITE_ROW ){
    int id, rid;
    const char *zName;

    id = db_column_int(&q, 0);
    zName = db_column_text(&q, 1);
    rid = db_column_int(&q, 2);
    if( promptFlag ){
      if( file_size(zName)>=0 ){
        Blob ans;
        char *zMsg;
        char cReply;
        zMsg = mprintf("overwrite %s (a=always/y/N)? ", zName);
        prompt_user(zMsg, &ans);
        free(zMsg);
        cReply = blob_str(&ans)[0];
        blob_reset(&ans);
        if( cReply=='a' || cReply=='A' ){
          promptFlag = 0;
          cReply = 'y';
        }
        if( cReply=='n' || cReply=='N' ) continue;
      }
    }
    content_get(rid, &content);
    if( verbose ) printf("%s\n", &zName[nRepos]);
    blob_write_to_file(&content, zName);
    blob_reset(&content);
    db_multi_exec("UPDATE vfile SET mtime=%lld WHERE id=%d",
                  file_mtime(zName), id);
  }