# 2007 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.

#

#***********************************************************************

# 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.

#

# $Id: corrupt3.test,v 1.2 2007/04/06 21:42:22 drh Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

# We must have the page_size pragma for these tests to work.

#

ifcapable !pager_pragmas {

  finish_test

  return

}

# Create a database with an overflow page.

#

do_test corrupt3-1.1 {

  set bigstring [string repeat 0123456789 200]

  execsql {

    PRAGMA auto_vacuum=OFF;

    PRAGMA page_size=1024;

    CREATE TABLE t1(x);

    INSERT INTO t1 VALUES($bigstring);

  }

  file size test.db

} [expr {1024*3}]

# Verify that the file format is as we expect.  The page size

# should be 1024 bytes.  The only record should have a single

# overflow page.  The overflow page is page 3.  The pointer to

# the overflow page is on the last 4 bytes of page 2.

#

do_test corrupt3-1.2 {

  hexio_get_int [hexio_read test.db 16 2]

} 1024   ;# The page size is 1024

do_test corrupt3-1.3 {

  hexio_get_int [hexio_read test.db 20 1]

} 0      ;# Unused bytes per page is 0

do_test corrupt3-1.4 {

  hexio_get_int [hexio_read test.db 2044 4]

} 3      ;# Overflow page is 3

do_test corrupt3-1.5 {

  hexio_get_int [hexio_read test.db 2048 4]

} 0      ;# First chained overflow is 0

integrity_check corrupt3-1.6

# Make the overflow chain loop back on itself.   See if the

# corruption is detected.   (Actually, the last pointer in

# an overflow chain is ignored, so this is not an error.)

#

do_test corrupt3-1.7 {

  db close

  hexio_write test.db 2048 [hexio_render_int32 3]

  sqlite3 db test.db

  catchsql {

    SELECT x FROM t1

  }

} [list 0 $bigstring]

integrity_check corrupt3-1.8

# Change the pointer for the first page of the overflow

# change to be a non-existant page.

#

do_test corrupt3-1.9 {

  db close

  hexio_write test.db 2044 [hexio_render_int32 4]

  sqlite3 db test.db

  catchsql {

    SELECT substr(x,1,10) FROM t1

  }

} [list 0 0123456789]

do_test corrupt3-1.10 {

  catchsql {

    PRAGMA integrity_check

  }

} {0 {{*** in database main ***

On tree page 2 cell 0: invalid page number 4

Page 3 is never used}}}

do_test corrupt3-1.11 {

  db close

  hexio_write test.db 2044 [hexio_render_int32 0]

  sqlite3 db test.db

  catchsql {

    SELECT substr(x,1,10) FROM t1

  }

} [list 1 {database disk image is malformed}]

do_test corrupt3-1.12 {

  catchsql {

    PRAGMA integrity_check

  }

} {0 {{*** in database main ***

On tree page 2 cell 0: 1 of 1 pages missing from overflow list starting at 0

Page 3 is never used}}}

finish_test