int sqlite3VdbeCursorMoveto(VdbeCursor **pp, int *piCol){
  VdbeCursor *p = *pp;
  assert( p->eCurType==CURTYPE_BTREE || p->eCurType==CURTYPE_PSEUDO );
  if( p->deferredMoveto ){
    int iMap;
    if( p->aAltMap && (iMap = p->aAltMap[1+*piCol])>0 ){
      *pp = p->pAltCursor;
      *piCol = iMap - 1;
      return SQLITE_OK;
    }
    return handleDeferredMoveto(p);
  }
  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
    return handleMovedCursor(p);
  }
  return SQLITE_OK;
}