SQLite

  }
  set rc
}

proc do_rbu_vacuum_test {tn step {statedb state.db}} {
  forcedelete $statedb
  if {$statedb=="" && $step==1} breakpoint
  uplevel [list do_test $tn.1 [string map [list %state% $statedb %step% $step] {
    if {%step%==0} { sqlite3rbu_vacuum rbu test.db {%state%}}
    while 1 {
      if {%step%==1} { sqlite3rbu_vacuum rbu test.db {%state%}}
      set state [rbu state]
      check_prestep_state test.db $state
      set rc [rbu step]
      check_poststep_state $rc test.db $state
      if {$rc!="SQLITE_OK"} break
      if {%step%==1} { rbu close }
    }
    rbu close
  }] {SQLITE_DONE}]

  uplevel [list do_execsql_test $tn.2 {
    PRAGMA integrity_check
  } ok]

    SELECT * FROM t1 ORDER BY %A%;
  } {
    1 10 {} b   7 8 4 d   10 11 12 e   13 14 {} f
  }

  set step 0
  do_rbu_vacuum_test $tn.1.5 0

  do_test $tn.1.6 {
    execsql { PRAGMA integrity_check }
  } {ok}
  }]
}

finish_test

        if( i!=iOrder ){
          SWAP(int, pIter->aiSrcOrder[i], pIter->aiSrcOrder[iOrder]);
          SWAP(char*, pIter->azTblCol[i], pIter->azTblCol[iOrder]);
        }

        pIter->azTblType[iOrder] = rbuStrndup(zType, &p->rc);
        assert( iPk>=0 );
        pIter->abTblPk[iOrder] = (u8)iPk;
        pIter->abNotNull[iOrder] = (u8)bNotNull || (iPk!=0);
        iOrder++;
      }
    }

    rbuFinalize(p, pStmt);
    rbuObjIterCacheIndexedCols(p, pIter);

  for(i=0; i<pIter->nTblCol; i++){
    const char *z = pIter->azTblCol[i];
    zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z);
    zSep = ", ";
  }
  return zList;
}

static char *rbuObjIterGetPkList(
  sqlite3rbu *p,                  /* RBU object */
  RbuObjIter *pIter,              /* Object iterator for column names */
  const char *zExtra
){
  int iPk = 1;
  char *zRet = 0;
  const char *zSep = "";
  while( 1 ){
    int i;
    for(i=0; i<pIter->nTblCol; i++){
      if( (int)pIter->abTblPk[i]==iPk ){
        const char *zCol = pIter->azTblCol[i];
        zRet = rbuMPrintf(p, "%z%s\"%w\"%s", zRet, zSep, zCol, zExtra);
        zSep = ", ";
      }
    }
    if( i==pIter->nTblCol ) break;
    iPk++;
  }
  return zRet;
}

static char *rbuVacuumTableStart(
  sqlite3rbu *p, 
  RbuObjIter *pIter,
  int bRowid,
  const char *zWrite
){
  sqlite3_stmt *pMax = 0;
  char *zRet = 0;
  if( bRowid ){
    p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, 
        sqlite3_mprintf(
          "SELECT max(_rowid_) FROM \"%s%w\"", zWrite, pIter->zTbl
        )
    );
    if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
      sqlite3_int64 iMax = sqlite3_column_int64(pMax, 0);
      zRet = rbuMPrintf(p, " WHERE _rowid_ > %lld ", iMax);
    }
    rbuFinalize(p, pMax);
  }else{
    char *zOrder = 0;
    char *zSelect = 0;
    char *zList = 0;
    int iPk = 1;
    const char *zSep = "";
    const char *zSep2 = "";
    while( 1 ){
      int i;
      for(i=0; i<pIter->nTblCol; i++){
        if( (int)pIter->abTblPk[i]==iPk ){
          const char *zCol = pIter->azTblCol[i];
          zOrder = rbuMPrintf(p, "%z%s\"%w\" DESC", zOrder, zSep, zCol);
          zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, zCol);
          zSelect = rbuMPrintf(p, "%z%squote(\"%w\")", zSelect, zSep2, zCol);
          zSep = ", ";
          zSep2 = "||','||";
        }
      }
      if( i==pIter->nTblCol ) break;
      iPk++;
    }

    if( p->rc==SQLITE_OK ){
      p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, 
          sqlite3_mprintf(
            "SELECT %s FROM \"%s%w\" ORDER BY %s LIMIT 1", 
                zSelect, zWrite, pIter->zTbl, zOrder
          )
      );
      if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){
        const char *zVal = (const char*)sqlite3_column_text(pMax, 0);
        zRet = rbuMPrintf(p, " WHERE (%s) > (%s) ", zList, zVal);
      }
      rbuFinalize(p, pMax);
    }

    sqlite3_free(zOrder);
    sqlite3_free(zSelect);
    sqlite3_free(zList);
  }
  return zRet;
}

/*
** This function is used to create a SELECT list (the list of SQL 
** expressions that follows a SELECT keyword) for a SELECT statement 
** used to read from an data_xxx or rbu_tmp_xxx table while updating the 
** index object currently indicated by the iterator object passed as the 
** second argument. A "PRAGMA index_xinfo = <idxname>" statement is used 

        rbuObjIterPrepareTmpInsert(p, pIter, zCollist, zRbuRowid);
      }

      /* Create the SELECT statement to read keys from data_xxx */
      if( p->rc==SQLITE_OK ){
        const char *zRbuRowid = "";
        char *zStart = 0;
        char *zOrder = 0;
        if( bRbuRowid ){
          zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid";
        }

        if( rbuIsVacuum(p) ){
          if( nOffset ){
            zStart = rbuVacuumTableStart(p, pIter, bRbuRowid, zWrite);
            if( zStart ){
              sqlite3_free(zLimit);
              zLimit = 0;
            }
          }
          if( bRbuRowid ){
            zOrder = rbuMPrintf(p, "_rowid_");
          }else{
            zOrder = rbuObjIterGetPkList(p, pIter, "");
          }
        }

        if( p->rc==SQLITE_OK ){
          p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz,
              sqlite3_mprintf(
                "SELECT %s,%s rbu_control%s FROM '%q'%s %s %s %s",
                zCollist, 
                (rbuIsVacuum(p) ? "0 AS " : ""),
                zRbuRowid,
                pIter->zDataTbl, (zStart ? zStart : ""), 
                (zOrder ? "ORDER BY" : ""), zOrder,
                zLimit
              )
          );
        }
        sqlite3_free(zStart);
        sqlite3_free(zOrder);
      }

      sqlite3_free(zWhere);
      sqlite3_free(zOldlist);
      sqlite3_free(zNewlist);
      sqlite3_free(zBindings);
    }