** Other options:
**
**   --detail                Show additional details of the merge
**
**   --binary GLOBPATTERN    Treat files that match GLOBPATTERN as binary
**                           and do not try to merge parallel changes.  This
**                           option overrides the "binary-glob" setting.
**
**   --nochange | -n         Dryrun:  do not actually make any changes; just
**                           show what would have happened.
*/
void merge_cmd(void){
  int vid;              /* Current version */
  int mid;              /* Version we are merging against */
  int pid;              /* The pivot version - most recent common ancestor */
  int detailFlag;       /* True if the --detail option is present */
  int pickFlag;         /* True if the --cherrypick option is present */
  int backoutFlag;      /* True if the --backout option is present */
  int nochangeFlag;     /* True if the --nochange or -n option is present */
  const char *zBinGlob; /* The value of --binary */
  Stmt q;

  detailFlag = find_option("detail",0,0)!=0;
  pickFlag = find_option("cherrypick",0,0)!=0;
  backoutFlag = find_option("backout",0,0)!=0;
  zBinGlob = find_option("binary",0,1);
  nochangeFlag = find_option("nochange","n",0)!=0;
  if( g.argc!=3 ){
    usage("VERSION");
  }
  db_must_be_within_tree();
  if( zBinGlob==0 ) zBinGlob = db_get("binary-glob",0);
  vid = db_lget_int("checkout", 0);
  if( vid==0 ){

      "  SELECT %d,3,0,rid,mrid,pathname FROM vfile WHERE id=%d",
      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);
    if( !nochangeFlag ){
      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.
  */
  db_prepare(&q,
    "SELECT idv, ridm FROM fv"
    " WHERE idp>0 AND idv>0 AND idm>0"
    "   AND ridm!=ridp AND ridv=ridp AND NOT chnged"
  );
  while( db_step(&q)==SQLITE_ROW ){
    int idv = db_column_int(&q, 0);
    int ridm = db_column_int(&q, 1);
    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);
    if( !nochangeFlag ){
      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
  */

    if( isBinary ){
      rc = -1;
      blob_zero(&r);
    }else{
      rc = blob_merge(&p, &m, &v, &r);
    }
    if( rc>=0 ){
      if( !nochangeFlag ) blob_write_to_file(&r, zFullPath);
      if( rc>0 ){
        printf("***** %d merge conflicts in %s\n", rc, zName);
      }
    }else{
      printf("***** Cannot merge binary file %s\n", zName);
    }
    free(zName);

  ** Clean up the mid and pid VFILE entries.  Then commit the changes.
  */
  db_multi_exec("DELETE FROM vfile WHERE vid!=%d", vid);
  if( !pickFlag ){
    db_multi_exec("INSERT OR IGNORE INTO vmerge(id,merge) VALUES(0,%d)", mid);
  }
  undo_finish();
  db_end_transaction(nochangeFlag);
}