# 2007 Dec 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 contains test cases for stressing database

 # changes that involve side effects that delete rows from

 # the table being changed.  Ticket #2832 shows that in

 # older versions of SQLite that behavior was implemented

 # incorrectly and resulted in corrupt database files.

 #

 # $Id: sidedelete.test,v 1.2 2008/08/04 03:51:24 danielk1977 Exp $

 #

 set testdir [file dirname $argv0]

 source $testdir/tester.tcl

 # The sequence table is created to store a sequence of integers

 # starting with 1.  This is used to reinitialize other tables

 # as part of other tests.

 #

 do_test sidedelete-1.1 {

   execsql {

     CREATE TABLE sequence(a INTEGER PRIMARY KEY);

     INSERT INTO sequence VALUES(1);

     INSERT INTO sequence VALUES(2);

   }

   for {set i 0} {$i<8} {incr i} {

     execsql {

       INSERT INTO sequence SELECT a+(SELECT max(a) FROM sequence) FROM sequence;

     }

   }

   execsql {SELECT count(*) FROM sequence}

 } {512}

 # Make a series of changes using an UPDATE OR REPLACE and a

 # correlated subquery.  This would cause database corruption

 # prior to the fix for ticket #2832.

 #

 do_test sidedelete-2.0 {

   execsql {

     CREATE TABLE t1(a PRIMARY KEY, b);

     CREATE TABLE chng(a PRIMARY KEY, b);

     SELECT count(*) FROM t1;

     SELECT count(*) FROM chng;

   }

 } {0 0}

 for {set i 2} {$i<=100} {incr i} {

   set n [expr {($i+2)/2}]

   do_test sidedelete-2.$i.1 {

     execsql {

       DELETE FROM t1;

       INSERT INTO t1 SELECT a, a FROM sequence WHERE a<=$i;

       DELETE FROM chng;

       INSERT INTO chng SELECT a*2, a*2+1 FROM sequence WHERE a<=$i/2;

       UPDATE OR REPLACE t1 SET a=(SELECT b FROM chng WHERE a=t1.a);

       SELECT count(*), sum(a) FROM t1;

     }

   } [list $n [expr {$n*$n-1}]]

   integrity_check sidedelete-2.$i.2

 }

 # This will cause stacks leaks but not database corruption prior

 # to the #2832 fix.

 #

 do_test sidedelete-3.0 {

   execsql {

      DROP TABLE t1;

      CREATE TABLE t1(a PRIMARY KEY);

      SELECT * FROM t1;

   }

 } {}

 for {set i 1} {$i<=100} {incr i} {

   set n [expr {($i+1)/2}]

   do_test sidedelete-3.$i.1 {

     execsql {

       DELETE FROM t1;

       INSERT INTO t1 SELECT a FROM sequence WHERE a<=$i;

       UPDATE OR REPLACE t1 SET a=a+1;

       SELECT count(*), sum(a) FROM t1;

     }

   } [list $n [expr {$n*($n+1)}]]

   integrity_check sidedelete-3.$i.2

 }

 finish_test