# 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