SQLite

/*
** 2004 April 6
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** $Id: btree.c,v 1.595 2009/04/11 16:06:15 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

  assert( pBt->usableSize > 4 );
  ovflPageSize = pBt->usableSize - 4;
  nOvfl = (info.nPayload - info.nLocal + ovflPageSize - 1)/ovflPageSize;
  assert( ovflPgno==0 || nOvfl>0 );
  while( nOvfl-- ){
    Pgno iNext = 0;
    MemPage *pOvfl = 0;
    if( ovflPgno<2 || ovflPgno>pagerPagecount(pBt) ){
      /* 0 is not a legal page number and page 1 cannot be an 
      ** overflow page. Therefore if ovflPgno<2 or past the end of the 
      ** file the database must be corrupt. */
      return SQLITE_CORRUPT_BKPT;
    }
    if( nOvfl ){
      rc = getOverflowPage(pBt, ovflPgno, &pOvfl, &iNext);
      if( rc ) return rc;
    }
    rc = freePage2(pBt, pOvfl, ovflPgno);

# This file implements regression tests for SQLite library.
#
# This file implements tests to make sure SQLite does not crash or
# segfault if it sees a corrupt database file.  It creates a base
# data base file, then tests that single byte corruptions in 
# increasingly larger quantities are handled gracefully.
#
# $Id: corruptC.test,v 1.11 2009/04/11 16:06:15 danielk1977 Exp $

catch {file delete -force test.db test.db-journal test.bu}

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Construct a compact, dense database for testing.

  # insert corrupt byte(s)
  hexio_write test.db 102 [format %02x 0x12]
  
  sqlite3 db test.db
  catchsql {BEGIN; CREATE TABLE t3 AS SELECT x,3 as y FROM t2 WHERE rowid%5!=0; ROLLBACK;}
} {1 {database disk image is malformed}}

do_test corruptC-2.14 {
  db close
  copy_file test.bu test.db

  sqlite3 db test.db
  set blob [string repeat abcdefghij 10000]
  execsql { INSERT INTO t1 VALUES (1, $blob) }

  sqlite3 db test.db
  set filesize [file size test.db]
  hexio_write test.db [expr $filesize-2048] 00000001
  catchsql {DELETE FROM t1 WHERE rowid = (SELECT max(rowid) FROM t1)}
} {1 {database disk image is malformed}}

#
# now test for a series of quasi-random seeds
for {set tn 0} {$tn<1024} {incr tn 1} {

  # setup for test
  db close