# 2007 May 12

#

# 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 tests a special case in the b-tree code that can be

# hit by the "IN" operator (or EXISTS, NOT IN, etc.).

#

# $Id: in2.test,v 1.3 2008/07/12 14:52:20 drh Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

do_test in2-1 {

  execsql {

    CREATE TABLE a(i INTEGER PRIMARY KEY, a);

  }

} {}

set ::N 2000

do_test in2-2 {

  db transaction {

    for {set ::ii 0} {$::ii < $::N} {incr ::ii} {

      execsql {INSERT INTO a VALUES($::ii, $::ii)}

    }

    execsql {INSERT INTO a VALUES(4000, '')}

    for {set ::ii 0} {$::ii < $::N} {incr ::ii} {

      set ::t [format "x%04d" $ii]

      execsql {INSERT INTO a VALUES(NULL, $::t)}

    }

  }

} {}

# Each iteration of this loop builds a slightly different b-tree to

# evaluate the "IN (...)" operator in the SQL statement. The contents

# of the b-tree are (in sorted order):

#

#     $::ii integers.

#     a string of zero length.

#     $::N short strings.

#

# Records are inserted in sorted order.

#

# The string of zero-length is stored in a b-tree cell with 3 bytes

# of payload. Moving this cell from a leaf node to a internal node 

# during b-tree balancing was causing an assertion failure. 

#

# This bug only applied to b-trees generated to evaluate IN (..) 

# clauses, as it is impossible for persistent b-trees (SQL tables + 

# indices) to contain cells smaller than 4 bytes.

#

for {set ::ii 3} {$::ii < $::N} {incr ::ii} {

  do_test in2-$::ii {

    execsql {

      SELECT 1 IN (SELECT a FROM a WHERE (i < $::ii) OR (i >= $::N))

    }

  } {1}

}

finish_test