SQLite

      nWalSize = (pWal->mxWalSize-WAL_HDRSIZE+pWal->szPage+WAL_FRAME_HDRSIZE-1) 
        / (pWal->szPage+WAL_FRAME_HDRSIZE);
      nWalSize = MAX(nWalSize, 1);
    }

    if( walidxGetMxFrame(&pWal->hdr, iApp)>=nWalSize ){
      volatile WalCkptInfo *pInfo = walCkptInfo(pWal);
      u32 mxFrame = walidxGetMxFrame(&pWal->hdr, !iApp);
      if( mxFrame==0 || pInfo->nBackfill ){
        rc = wal2RestartOk(pWal, iApp);
        if( rc==SQLITE_OK ){
          int iNew = !iApp;
          pWal->nCkpt++;
          walidxSetFile(&pWal->hdr, iNew);
          walidxSetMxFrame(&pWal->hdr, iNew, 0);
          sqlite3Put4byte((u8*)&pWal->hdr.aSalt[0], pWal->hdr.aFrameCksum[0]);

    }
  }

  /* Copy data from the log to the database file. */
  if( rc==SQLITE_OK ){
    int iCkpt = walidxGetFile(&pWal->hdr);

    if( (walPagesize(pWal)!=nBuf) 
     && ((pWal->hdr.mxFrame2 & 0x7FFFFFFF) || pWal->hdr.mxFrame)
    ){
      rc = SQLITE_CORRUPT_BKPT;
    }else{
      rc = walCheckpoint(pWal, db, eMode2, xBusy2, pBusyArg, sync_flags, zBuf);
    }

    /* If no error occurred, set the output variables. */
    if( rc==SQLITE_OK || rc==SQLITE_BUSY ){

  5   2048    1
  6   4096    1
  7   8192    1
  8  16384    1
  9  32768    1
 10  65536    1
 11 131072    0
 12   1016    0
} {

  if {$::SQLITE_MAX_PAGE_SIZE < $pgsz} {
    set works 0
  }

  for {set pg 1} {$pg <= 3} {incr pg} {
    forcecopy testX.db test.db
    forcedelete test.db-wal

    # Check that the database now exists and consists of three pages. And
    # that there is no associated wal file.
    #
    do_test wal-18.2.$tn.$pg.1 { file exists test.db-wal } 0
    do_test wal-18.2.$tn.$pg.2 { file exists test.db } 1
    do_test wal-18.2.$tn.$pg.3 { file size test.db } [expr 1024*3]

    do_test wal-18.2.$tn.$pg.4 {

      # Create a wal file that contains a single frame (database page
      # number $pg) with the commit flag set. The frame checksum is
      # correct, but the contents of the database page are corrupt.
      #
      # The page-size in the log file header is set to $pgsz. If the

      set fd [open test.db-wal w]
      fconfigure $fd -encoding binary -translation binary
      puts -nonewline $fd $walhdr
      puts -nonewline $fd $framehdr
      puts -nonewline $fd $framebody
      close $fd

      file size test.db-wal
    } [wal_file_size 1 $pgsz]

    do_test wal-18.2.$tn.$pg.5 {
      sqlite3 db test.db
      set rc [catch { db one {PRAGMA integrity_check} } msg]
      expr { $rc!=0 || $msg!="ok" }
    } $works
 
    db close
  }
}

#-------------------------------------------------------------------------
# The following test - wal-19.* - fixes a bug that was present during
# development.

  4 test.db2-wal2   salt1
} {
  do_test 1.6.$tn {
    forcecopy test.db test.db2
    forcecopy test.db-wal2 test.db2-wal
    forcecopy test.db-wal test.db2-wal2
    wal_incr_hdrfield $file $field

    sqlite3 db2 test.db2
    execsql {
      SELECT sum(x) FROM t1;
      SELECT sum(x) FROM t2;
    } db2
  } [list $H $L]
  db2 close

    forcecopy test.db-wal2 test.db2-wal
    forcecopy test.db-wal test.db2-wal2

    wal_set_nckpt test.db2-wal2 $nCkpt2
    wal_set_nckpt test.db2-wal  $nCkpt1
    wal_set_follow test.db2-wal test.db2-wal2



    sqlite3 db2 test.db2
    execsql {
      SELECT sum(x) FROM t1;
      SELECT sum(x) FROM t2;
    } db2
  } $res
  db2 close
}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 1.8.1 {
  PRAGMA autovacuum = 0;
  PRAGMA page_size = 4096;
  CREATE TABLE t1(x);
  CREATE TABLE t2(x);
  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
    INSERT INTO t1 SELECT i FROM s;
  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
    INSERT INTO t2 SELECT i FROM s;

  PRAGMA journal_mode = wal2;
  PRAGMA journal_size_limit = 10000;

  WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<1500 )
    INSERT INTO t2 SELECT i FROM s;
} {wal2 10000}

do_test 1.8.2 {
  list [file size test.db-wal] [file size test.db-wal2]
} {24752 0}

do_execsql_test 1.8.3 { PRAGMA user_version = 123 }
do_test 1.8.4 {
  list [file size test.db-wal] [file size test.db-wal2]
} {24752 4152}

do_test 1.8.5 {
  hexio_write test.db-wal2 [expr 56+16] 0400
  fix_wal_cksums test.db-wal2
} {}

do_test 1.8.6 {
  forcecopy test.db test.db2
  forcecopy test.db-wal test.db2-wal
  forcecopy test.db-wal2 test.db2-wal2
  sqlite3 db2 test.db2
  catchsql { SELECT * FROM sqlite_master } db2
} {1 {database disk image is malformed}}
db2 close

finish_test

    do_test 1.6 {
      execsql BEGIN
      set SNAPSHOT [sqlite3_snapshot_get_blob db main]
      sqlite3_snapshot_open_blob db main $SNAPSHOT
      execsql COMMIT
    } {}
  } else {
    do_test 2.6.1 {
      execsql BEGIN
      set res [
        list [catch { sqlite3_snapshot_open_blob db main $SNAPSHOT } msg] $msg
      ]
      execsql COMMIT
      set res
    } {1 SQLITE_ERROR}
    do_test 2.6.2 {
      execsql BEGIN
      execsql {SELECT * FROM sqlite_master}
      set res [
        list [catch { sqlite3_snapshot_open_blob db main $SNAPSHOT } msg] $msg
      ]
      execsql COMMIT
      set res
    } {1 SQLITE_ERROR}
  }