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1# 2007 May 12
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file tests a special case in the b-tree code that can be
12# hit by the "IN" operator (or EXISTS, NOT IN, etc.).
13#
14# $Id: in2.test,v 1.3 2008/07/12 14:52:20 drh Exp $
15
16set testdir [file dirname $argv0]
17source $testdir/tester.tcl
18
19do_test in2-1 {
20  execsql {
21    CREATE TABLE a(i INTEGER PRIMARY KEY, a);
22  }
23} {}
24
25set ::N 2000
26
27do_test in2-2 {
28  db transaction {
29    for {set ::ii 0} {$::ii < $::N} {incr ::ii} {
30      execsql {INSERT INTO a VALUES($::ii, $::ii)}
31    }
32    execsql {INSERT INTO a VALUES(4000, '')}
33
34    for {set ::ii 0} {$::ii < $::N} {incr ::ii} {
35      set ::t [format "x%04d" $ii]
36      execsql {INSERT INTO a VALUES(NULL, $::t)}
37    }
38  }
39} {}
40
41# Each iteration of this loop builds a slightly different b-tree to
42# evaluate the "IN (...)" operator in the SQL statement. The contents
43# of the b-tree are (in sorted order):
44#
45#     $::ii integers.
46#     a string of zero length.
47#     $::N short strings.
48#
49# Records are inserted in sorted order.
50#
51# The string of zero-length is stored in a b-tree cell with 3 bytes
52# of payload. Moving this cell from a leaf node to a internal node
53# during b-tree balancing was causing an assertion failure.
54#
55# This bug only applied to b-trees generated to evaluate IN (..)
56# clauses, as it is impossible for persistent b-trees (SQL tables +
57# indices) to contain cells smaller than 4 bytes.
58#
59for {set ::ii 3} {$::ii < $::N} {incr ::ii} {
60  do_test in2-$::ii {
61    execsql {
62      SELECT 1 IN (SELECT a FROM a WHERE (i < $::ii) OR (i >= $::N))
63    }
64  } {1}
65}
66
67finish_test
68