# 2008 June 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 cell offsets in a btree page.
#
# $Id: corrupt7.test,v 1.8 2009/08/10 10:18:08 danielk1977 Exp $

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

# This module uses hard-coded offsets which do not work if the reserved_bytes
# value is nonzero.
if {[nonzero_reserved_bytes]} {finish_test; return;}

# These tests deal with corrupt database files
#
database_may_be_corrupt

# We must have the page_size pragma for these tests to work.
#
ifcapable !pager_pragmas {
  finish_test
  return
}

# Create a simple, small database.
#
do_test corrupt7-1.1 {
  execsql {
    PRAGMA auto_vacuum=OFF;
    PRAGMA page_size=1024;
    CREATE TABLE t1(x);
    INSERT INTO t1(x) VALUES(1);
    INSERT INTO t1(x) VALUES(2);
    INSERT INTO t1(x) SELECT x+2 FROM t1;
    INSERT INTO t1(x) SELECT x+4 FROM t1;
    INSERT INTO t1(x) SELECT x+8 FROM t1;
  }
  file size test.db
} [expr {1024*2}]

# Verify that the file format is as we expect.  The page size
# should be 1024 bytes.
#
do_test corrupt7-1.2 {
  hexio_get_int [hexio_read test.db 16 2]
} 1024   ;# The page size is 1024
do_test corrupt7-1.3 {
  hexio_get_int [hexio_read test.db 20 1]
} 0      ;# Unused bytes per page is 0

integrity_check corrupt7-1.4

# Deliberately corrupt some of the cell offsets in the btree page
# on page 2 of the database.
do_test corrupt7-2.1 {
  db close
  hexio_write test.db 1062 FF
  sqlite3 db test.db
  db eval {PRAGMA integrity_check(1)}
} {{*** in database main ***
On tree page 2 cell 15: Offset 65457 out of range 945..1020}}
do_test corrupt7-2.2 {
  db close
  hexio_write test.db 1062 04
  sqlite3 db test.db
  db eval {PRAGMA integrity_check(1)}
} {{*** in database main ***
On tree page 2 cell 15: Offset 1201 out of range 945..1020}}
  
# The code path that was causing the buffer overrun that this test
# case was checking for was removed.
#
#do_test corrupt7-3.1 {
#  execsql {
#    DROP TABLE t1;
#    CREATE TABLE t1(a, b);
#    INSERT INTO t1 VALUES(1, 'one');
#    INSERT INTO t1 VALUES(100, 'one hundred');
#    INSERT INTO t1 VALUES(100000, 'one hundred thousand');
#    CREATE INDEX i1 ON t1(b);
#  }
#  db close
#
#  # Locate the 3rd cell in the index.
#  set cell_offset [hexio_get_int [hexio_read test.db [expr 1024*2 + 12] 2]]
#  incr cell_offset [expr 1024*2]
#  incr cell_offset 1
#
#  # This write corrupts the "header-size" field of the database record
#  # stored in the index cell. At one point this was causing sqlite to 
#  # reference invalid memory.
#  hexio_write test.db $cell_offset FFFF7F
#  
#  sqlite3 db test.db
#  catchsql {
#    SELECT b FROM t1 WHERE b > 'o' AND b < 'p';
#  }
#} {1 {database disk image is malformed}}

finish_test
