** 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 1.479 2008/07/11 16:15:18 drh 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"

................................................................................
  ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
  ** page pointer.
  */
  pBt->maxLocal = (pBt->usableSize-12)*64/255 - 23;
  pBt->minLocal = (pBt->usableSize-12)*32/255 - 23;
  pBt->maxLeaf = pBt->usableSize - 35;
  pBt->minLeaf = (pBt->usableSize-12)*32/255 - 23;
  if( pBt->minLocal>pBt->maxLocal || pBt->maxLocal<0 ){
    goto page1_init_failed;
  }
  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;
  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;

** 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 1.480 2008/07/11 16:39:23 drh 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"

................................................................................
  ** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
  ** page pointer.
  */
  pBt->maxLocal = (pBt->usableSize-12)*64/255 - 23;
  pBt->minLocal = (pBt->usableSize-12)*32/255 - 23;
  pBt->maxLeaf = pBt->usableSize - 35;
  pBt->minLeaf = (pBt->usableSize-12)*32/255 - 23;



  assert( pBt->maxLeaf + 23 <= MX_CELL_SIZE(pBt) );
  pBt->pPage1 = pPage1;
  return SQLITE_OK;

page1_init_failed:
  releasePage(pPage1);
  pBt->pPage1 = 0;

# 2008 July 11
#
# 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.
#
#***********************************************************************
# 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 specifically focuses
# on corrupt database headers.
#
# $Id: corruptA.test,v 1.1 2008/07/11 16:39:23 drh Exp $

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


# Create a database to work with.
#
do_test corruptA-1.1 {
  execsql {
    CREATE TABLE t1(x);
    INSERT INTO t1(x) VALUES(1);
  }
  expr {[file size test.db]>=1024}
} {1}
integrity_check corruptA-1.2

# Corrupt the file header in various ways and make sure the corruption
# is detected when opening the database file.
#
db close
file copy -force test.db test.db-template

do_test corruptA-2.1 {
  file copy -force test.db-template test.db
  hexio_write test.db 19 02   ;# the read format number
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 
do_test corruptA-2.2 {
  db close
  file copy -force test.db-template test.db
  hexio_write test.db 21 41   ;# max embedded payload fraction
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 
do_test corruptA-2.3 {
  db close
  file copy -force test.db-template test.db
  hexio_write test.db 22 1f   ;# min embedded payload fraction
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 
do_test corruptA-2.4 {
  db close
  file copy -force test.db-template test.db
  hexio_write test.db 23 21   ;# min leaf payload fraction
  sqlite3 db test.db
  catchsql {SELECT * FROM t1}  
} {1 {file is encrypted or is not a database}}
 

finish_test