** 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.
**
*************************************************************************
** $Id: btree.c,v 1.535 2008/11/13 14:28:29 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
  cbrk = get2byte(&data[hdr+5]);
  memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
  cbrk = usableSize;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
    if( pc>=pPage->pBt->usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
    size = cellSizePtr(pPage, &temp[pc]);
    cbrk -= size;
    if( cbrk<cellOffset+2*nCell || pc+size>usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
................................................................................
** Return a section of the pPage->aData to the freelist.
** The first byte of the new free block is pPage->aDisk[start]
** and the size of the block is "size" bytes.
**
** Most of the effort here is involved in coalesing adjacent
** free blocks into a single big free block.
*/
static void freeSpace(MemPage *pPage, int start, int size){
  int addr, pbegin, hdr;
  unsigned char *data = pPage->aData;

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( start>=pPage->hdrOffset+6+(pPage->leaf?0:4) );
  assert( (start + size)<=pPage->pBt->usableSize );
................................................................................
#endif

  /* Add the space back into the linked list of freeblocks */
  hdr = pPage->hdrOffset;
  addr = hdr + 1;
  while( (pbegin = get2byte(&data[addr]))<start && pbegin>0 ){
    assert( pbegin<=pPage->pBt->usableSize-4 );
    assert( pbegin>addr );


    addr = pbegin;
  }
  assert( pbegin<=pPage->pBt->usableSize-4 );


  assert( pbegin>addr || pbegin==0 );
  put2byte(&data[addr], start);
  put2byte(&data[start], pbegin);
  put2byte(&data[start+2], size);
  pPage->nFree += size;

  /* Coalesce adjacent free blocks */
................................................................................
    int pnext, psize;
    assert( pbegin>addr );
    assert( pbegin<=pPage->pBt->usableSize-4 );
    pnext = get2byte(&data[pbegin]);
    psize = get2byte(&data[pbegin+2]);
    if( pbegin + psize + 3 >= pnext && pnext>0 ){
      int frag = pnext - (pbegin+psize);
      assert( frag<=data[pPage->hdrOffset+7] );


      data[pPage->hdrOffset+7] -= frag;
      put2byte(&data[pbegin], get2byte(&data[pnext]));
      put2byte(&data[pbegin+2], pnext+get2byte(&data[pnext+2])-pbegin);
    }else{
      addr = pbegin;
    }
  }
................................................................................
  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
    int top;
    pbegin = get2byte(&data[hdr+1]);
    memcpy(&data[hdr+1], &data[pbegin], 2);
    top = get2byte(&data[hdr+5]);
    put2byte(&data[hdr+5], top + get2byte(&data[pbegin+2]));
  }

}

/*
** Decode the flags byte (the first byte of the header) for a page
** and initialize fields of the MemPage structure accordingly.
**
** Only the following combinations are supported.  Anything different
................................................................................
** "sz" must be the number of bytes in the cell.
*/
static int dropCell(MemPage *pPage, int idx, int sz){
  int i;          /* Loop counter */
  int pc;         /* Offset to cell content of cell being deleted */
  u8 *data;       /* pPage->aData */
  u8 *ptr;        /* Used to move bytes around within data[] */


  assert( idx>=0 && idx<pPage->nCell );
  assert( sz==cellSize(pPage, idx) );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  data = pPage->aData;
  ptr = &data[pPage->cellOffset + 2*idx];
  pc = get2byte(ptr);
  if ( pc<=10 || pc+sz>pPage->pBt->usableSize ) {
    return SQLITE_CORRUPT_BKPT;
  }
  freeSpace(pPage, pc, sz);



  for(i=idx+1; i<pPage->nCell; i++, ptr+=2){
    ptr[0] = ptr[2];
    ptr[1] = ptr[3];
  }
  pPage->nCell--;
  put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
  pPage->nFree += 2;
................................................................................
                                   || !pCur->pagesShuffled );
      }
    }
    sqlite3BtreeReleaseTempCursor(&leafCur);
  }else{
    TRACE(("DELETE: table=%d delete from leaf %d\n",
       pCur->pgnoRoot, pPage->pgno));
    dropCell(pPage, idx, cellSizePtr(pPage, pCell));

    rc = balance(pCur, 0);

  }
  if( rc==SQLITE_OK ){
    moveToRoot(pCur);
  }
  return rc;
}

** 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.
**
*************************************************************************
** $Id: btree.c,v 1.536 2008/11/13 18:29:51 shane Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

................................................................................
  cbrk = get2byte(&data[hdr+5]);
  memcpy(&temp[cbrk], &data[cbrk], usableSize - cbrk);
  cbrk = usableSize;
  for(i=0; i<nCell; i++){
    u8 *pAddr;     /* The i-th cell pointer */
    pAddr = &data[cellOffset + i*2];
    pc = get2byte(pAddr);
    if( pc>=usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
    size = cellSizePtr(pPage, &temp[pc]);
    cbrk -= size;
    if( cbrk<cellOffset+2*nCell || pc+size>usableSize ){
      return SQLITE_CORRUPT_BKPT;
    }
................................................................................
** Return a section of the pPage->aData to the freelist.
** The first byte of the new free block is pPage->aDisk[start]
** and the size of the block is "size" bytes.
**
** Most of the effort here is involved in coalesing adjacent
** free blocks into a single big free block.
*/
static int freeSpace(MemPage *pPage, int start, int size){
  int addr, pbegin, hdr;
  unsigned char *data = pPage->aData;

  assert( pPage->pBt!=0 );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( start>=pPage->hdrOffset+6+(pPage->leaf?0:4) );
  assert( (start + size)<=pPage->pBt->usableSize );
................................................................................
#endif

  /* Add the space back into the linked list of freeblocks */
  hdr = pPage->hdrOffset;
  addr = hdr + 1;
  while( (pbegin = get2byte(&data[addr]))<start && pbegin>0 ){
    assert( pbegin<=pPage->pBt->usableSize-4 );
    if( pbegin<=addr ) {
      return SQLITE_CORRUPT_BKPT;
    }
    addr = pbegin;
  }
  if ( pbegin>pPage->pBt->usableSize-4 ) {
    return SQLITE_CORRUPT_BKPT;
  }
  assert( pbegin>addr || pbegin==0 );
  put2byte(&data[addr], start);
  put2byte(&data[start], pbegin);
  put2byte(&data[start+2], size);
  pPage->nFree += size;

  /* Coalesce adjacent free blocks */
................................................................................
    int pnext, psize;
    assert( pbegin>addr );
    assert( pbegin<=pPage->pBt->usableSize-4 );
    pnext = get2byte(&data[pbegin]);
    psize = get2byte(&data[pbegin+2]);
    if( pbegin + psize + 3 >= pnext && pnext>0 ){
      int frag = pnext - (pbegin+psize);
      if( (frag<0) || (frag>data[pPage->hdrOffset+7]) ){
        return SQLITE_CORRUPT_BKPT;
      }
      data[pPage->hdrOffset+7] -= frag;
      put2byte(&data[pbegin], get2byte(&data[pnext]));
      put2byte(&data[pbegin+2], pnext+get2byte(&data[pnext+2])-pbegin);
    }else{
      addr = pbegin;
    }
  }
................................................................................
  if( data[hdr+1]==data[hdr+5] && data[hdr+2]==data[hdr+6] ){
    int top;
    pbegin = get2byte(&data[hdr+1]);
    memcpy(&data[hdr+1], &data[pbegin], 2);
    top = get2byte(&data[hdr+5]);
    put2byte(&data[hdr+5], top + get2byte(&data[pbegin+2]));
  }
  return SQLITE_OK;
}

/*
** Decode the flags byte (the first byte of the header) for a page
** and initialize fields of the MemPage structure accordingly.
**
** Only the following combinations are supported.  Anything different
................................................................................
** "sz" must be the number of bytes in the cell.
*/
static int dropCell(MemPage *pPage, int idx, int sz){
  int i;          /* Loop counter */
  int pc;         /* Offset to cell content of cell being deleted */
  u8 *data;       /* pPage->aData */
  u8 *ptr;        /* Used to move bytes around within data[] */
  int rc;         /* The return code */

  assert( idx>=0 && idx<pPage->nCell );
  assert( sz==cellSize(pPage, idx) );
  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
  assert( sqlite3_mutex_held(pPage->pBt->mutex) );
  data = pPage->aData;
  ptr = &data[pPage->cellOffset + 2*idx];
  pc = get2byte(ptr);
  if ( (pc<pPage->hdrOffset+6+(pPage->leaf?0:4)) || (pc+sz>pPage->pBt->usableSize) ) {
    return SQLITE_CORRUPT_BKPT;
  }
  rc = freeSpace(pPage, pc, sz);
  if( rc!=SQLITE_OK ){
    return rc;
  }
  for(i=idx+1; i<pPage->nCell; i++, ptr+=2){
    ptr[0] = ptr[2];
    ptr[1] = ptr[3];
  }
  pPage->nCell--;
  put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
  pPage->nFree += 2;
................................................................................
                                   || !pCur->pagesShuffled );
      }
    }
    sqlite3BtreeReleaseTempCursor(&leafCur);
  }else{
    TRACE(("DELETE: table=%d delete from leaf %d\n",
       pCur->pgnoRoot, pPage->pgno));
    rc = dropCell(pPage, idx, cellSizePtr(pPage, pCell));
    if( rc==SQLITE_OK ){
      rc = balance(pCur, 0);
    }
  }
  if( rc==SQLITE_OK ){
    moveToRoot(pCur);
  }
  return rc;
}

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.501 2008/11/11 18:28:59 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
  Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
  Token **pUnqual     /* Write the unqualified object name here */
){
  int iDb;                    /* Database holding the object */
  sqlite3 *db = pParse->db;

  if( pName2 && pName2->n>0 ){
    assert( !db->init.busy );




    *pUnqual = pName2;
    iDb = sqlite3FindDb(db, pName1);
    if( iDb<0 ){
      sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
      pParse->nErr++;
      return -1;
    }

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.502 2008/11/13 18:29:51 shane Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
  Token *pName2,      /* The "yyy" in the name "xxx.yyy" */
  Token **pUnqual     /* Write the unqualified object name here */
){
  int iDb;                    /* Database holding the object */
  sqlite3 *db = pParse->db;

  if( pName2 && pName2->n>0 ){
    if( db->init.busy ) {
      sqlite3ErrorMsg(pParse, "corrupt database");
      pParse->nErr++;
      return -1;
    }
    *pUnqual = pName2;
    iDb = sqlite3FindDb(db, pName1);
    if( iDb<0 ){
      sqlite3ErrorMsg(pParse, "unknown database %T", pName1);
      pParse->nErr++;
      return -1;
    }

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.786 2008/11/05 16:37:35 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  if( pOp->p5 ){
    assert( p2>0 );
    assert( p2<=p->nMem );
    pIn2 = &p->aMem[p2];
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = pIn2->u.i;
    assert( p2>=2 );



  }
  assert( i>=0 );
  pCur = allocateCursor(p, i, &pOp[-1], iDb, 1);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, pCur->pCursor);
  if( pOp->p4type==P4_KEYINFO ){

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.787 2008/11/13 18:29:51 shane Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include "vdbeInt.h"

/*
** The following global variable is incremented every time a cursor
................................................................................
  }
  if( pOp->p5 ){
    assert( p2>0 );
    assert( p2<=p->nMem );
    pIn2 = &p->aMem[p2];
    sqlite3VdbeMemIntegerify(pIn2);
    p2 = pIn2->u.i;
    if( p2<2 ) {
      rc = SQLITE_CORRUPT_BKPT;
      goto abort_due_to_error;
    }
  }
  assert( i>=0 );
  pCur = allocateCursor(p, i, &pOp[-1], iDb, 1);
  if( pCur==0 ) goto no_mem;
  pCur->nullRow = 1;
  rc = sqlite3BtreeCursor(pX, p2, wrFlag, pOp->p4.p, pCur->pCursor);
  if( pOp->p4type==P4_KEYINFO ){

# 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 creates a base
# data base file, then tests that single byte corruptions in 
# increasingly larger quantities are handled gracefully.
#
# $Id: corruptC.test,v 1.8 2008/11/12 18:21:36 danielk1977 Exp $

catch {file delete -force test.db test.db-journal test.bu}

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

# Set a uniform random seed
expr srand(0)

# Construct a compact, dense database for testing.
#
do_test corruptC-1.1 {
  execsql {
    PRAGMA auto_vacuum = 0;
    BEGIN;
    CREATE TABLE t1(x,y);
................................................................................
ifcapable {integrityck} {
  integrity_check corruptC-1.2
}

# Generate random integer
#
proc random {range} {
    return [expr {round(rand()*$range)}]
}

# Copy file $from into $to
#
proc copy_file {from to} {
  set f [open $from]
  fconfigure $f -translation binary
  set t [open $to w]
  fconfigure $t -translation binary
  puts -nonewline $t [read $f [file size $from]]
  close $t
  close $f
}

# Setup for the tests.  Make a backup copy of the good database in test.bu.
#
db close
copy_file test.db test.bu
sqlite3 db test.db
set fsize [file size test.db]













#

# first test some specific corruption tests found from earlier runs

#

# test that a corrupt content offset size is handled (seed 5577)
do_test corruptC-2.1 {
  db close
  copy_file test.bu test.db

................................................................................
  # insert corrupt byte(s)
  hexio_write test.db 619 [format %02x 0xe2]
  hexio_write test.db 3150 [format %02x 0xa8]

  sqlite3 db test.db
  catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
} {1 {database disk image is malformed}}





#
# now test for a series of quasi-random seeds


#
for {set tn 0} {$tn<=1024} {incr tn 1} {




  # Set a quasi-random random seed
  expr srand($tn)

















































































  # setup for test
  db close
  copy_file test.bu test.db
  sqlite3 db test.db

  # Seek to a random location in the file, and write a random single byte
  # value.  Then do various operations on the file to make sure that
  # the database engine can handle the corruption gracefully.
  #
  set last 0
  for {set i 1} {$i<=1024 && !$last} {incr i 1} {

    # insert random byte at random location
    db close

    hexio_write test.db [random $fsize] [format %02x [random 255]]









    sqlite3 db test.db

    # do a few random operations to make sure that if 
    # they error, they error gracefully instead of crashing.
    do_test corruptC-3.$tn.$i.1 {
      catchsql {SELECT count(*) FROM sqlite_master}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.2 {
      catchsql {SELECT count(*) FROM t1}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.3 {
      catchsql {SELECT count(*) FROM t1 WHERE x>13}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.4 {
      catchsql {SELECT count(*) FROM t2}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.5 {
      catchsql {SELECT count(*) FROM t2 WHERE x<13}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.6 {
      catchsql {BEGIN; UPDATE t1 SET y=1; ROLLBACK;}
      set x {}
    } {}
    do_test corruptC-3.$tn.$i.7 {
      catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
      set x {}












    } {}

    # check the integrity of the database.
    # once the corruption is detected, we can stop.
    ifcapable {integrityck} {
      set res [ catchsql {PRAGMA integrity_check} ]
      set ans [lindex $res 1]
................................................................................
      }
    }

    # Check that no page references were leaked.
    # TBD:  need to figure out why this doesn't work
    # work with ROLLBACKs...
    if {0} {
      do_test corruptC-3.$tn.$i.8 {
        set bt [btree_from_db db]
        db_enter db
        array set stats [btree_pager_stats $bt]
        db_leave db
        set stats(ref)
      } {0}
    }

# 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 creates a base
# data base file, then tests that single byte corruptions in 
# increasingly larger quantities are handled gracefully.
#
# $Id: corruptC.test,v 1.9 2008/11/13 18:29:51 shane Exp $

catch {file delete -force test.db test.db-journal test.bu}

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




# Construct a compact, dense database for testing.
#
do_test corruptC-1.1 {
  execsql {
    PRAGMA auto_vacuum = 0;
    BEGIN;
    CREATE TABLE t1(x,y);
................................................................................
ifcapable {integrityck} {
  integrity_check corruptC-1.2
}

# Generate random integer
#
proc random {range} {
  return [expr {round(rand()*$range)}]
}

# Copy file $from into $to
#
proc copy_file {from to} {
  file copy -force $from $to






}

# Setup for the tests.  Make a backup copy of the good database in test.bu.
#
db close
copy_file test.db test.bu
sqlite3 db test.db
set fsize [file size test.db]

# Set a quasi-random random seed. 
if {[info exists SOAKTEST]} {
  # If we are doing SOAK tests, we want a different
  # random seed for each run.  Ideally we would like 
  # to use [clock clicks] or something like that here.
  set qseed [file mtime test.db]
} else {
  # If we are not doing soak tests,
  # make it repeatable.
  set qseed 0
}
expr srand($qseed)

#
# First test some specific corruption tests found from earlier runs
# with specific seeds.
#

# test that a corrupt content offset size is handled (seed 5577)
do_test corruptC-2.1 {
  db close
  copy_file test.bu test.db

................................................................................
  # insert corrupt byte(s)
  hexio_write test.db 619 [format %02x 0xe2]
  hexio_write test.db 3150 [format %02x 0xa8]

  sqlite3 db test.db
  catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
} {1 {database disk image is malformed}}

# corruption (seed 178692)
do_test corruptC-2.7 {
  db close
  copy_file test.bu test.db


  # insert corrupt byte(s)
  hexio_write test.db 3074 [format %02x 0xa0]


  sqlite3 db test.db
  catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
} {1 {database disk image is malformed}}



# corruption (seed 179069)
do_test corruptC-2.8 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 1393 [format %02x 0x7d]
  hexio_write test.db 84 [format %02x 0x19]
  hexio_write test.db 3287 [format %02x 0x3b]
  hexio_write test.db 2564 [format %02x 0xed]
  hexio_write test.db 2139 [format %02x 0x55]

  sqlite3 db test.db
  catchsql {BEGIN; DELETE FROM t1 WHERE x>13; ROLLBACK;}
} {1 {database disk image is malformed}}

# corruption (seed 170434)
do_test corruptC-2.9 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 2095 [format %02x 0xd6]

  sqlite3 db test.db
  catchsql {BEGIN; DELETE FROM t1 WHERE x>13; ROLLBACK;}
} {1 {database disk image is malformed}}

# corruption (seed 186504)
do_test corruptC-2.10 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 3130 [format %02x 0x02]
  
  sqlite3 db test.db
  catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
} {1 {database disk image is malformed}}

# corruption (seed 1589)
do_test corruptC-2.11 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 55 [format %02x 0xa7]
  
  sqlite3 db test.db
  catchsql {BEGIN; CREATE TABLE t3 AS SELECT x,3 as y FROM t2 WHERE rowid%5!=0; ROLLBACK;}
} {1 {database disk image is malformed}}

# corruption (seed 14166)
do_test corruptC-2.12 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 974 [format %02x 0x2e]
  
  sqlite3 db test.db
  catchsql {SELECT count(*) FROM sqlite_master;}
} {1 {malformed database schema (t1i1) - corrupt database}}

# corruption (seed 218803)
do_test corruptC-2.13 {
  db close
  copy_file test.bu test.db

  # insert corrupt byte(s)
  hexio_write test.db 102 [format %02x 0x12]
  
  sqlite3 db test.db
  catchsql {BEGIN; CREATE TABLE t3 AS SELECT x,3 as y FROM t2 WHERE rowid%5!=0; ROLLBACK;}
} {1 {database disk image is malformed}}


#
# now test for a series of quasi-random seeds
for {set tn 0} {$tn<1024} {incr tn 1} {

  # setup for test
  db close
  copy_file test.bu test.db
  sqlite3 db test.db

  # Seek to a random location in the file, and write a random single byte
  # value.  Then do various operations on the file to make sure that
  # the database engine can handle the corruption gracefully.
  #
  set last 0
  for {set i 1} {$i<=512 && !$last} {incr i 1} {

    # insert random byte at random location
    db close
    set roffset [random $fsize]
    set rbyte [format %02x [random 255]]

    # You can uncomment the following to have it trace
    # exactly how it's corrupting the file.  This is 
    # useful for generating the "seed specific" tests
    # above.
    # set rline "$roffset $rbyte"
    # puts stdout $rline

    hexio_write test.db $roffset $rbyte
    sqlite3 db test.db

    # do a few random operations to make sure that if 
    # they error, they error gracefully instead of crashing.
    do_test corruptC-3.$tn.($qseed).$i.1 {
      catchsql {SELECT count(*) FROM sqlite_master}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.2 {
      catchsql {SELECT count(*) FROM t1}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.3 {
      catchsql {SELECT count(*) FROM t1 WHERE x>13}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.4 {
      catchsql {SELECT count(*) FROM t2}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.5 {
      catchsql {SELECT count(*) FROM t2 WHERE x<13}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.6 {
      catchsql {BEGIN; UPDATE t1 SET y=1; ROLLBACK;}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.7 {
      catchsql {BEGIN; UPDATE t2 SET y='abcdef-uvwxyz'; ROLLBACK;}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.8 {
      catchsql {BEGIN; DELETE FROM t1 WHERE x>13; ROLLBACK;}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.9 {
      catchsql {BEGIN; DELETE FROM t2 WHERE x<13; ROLLBACK;}
      set x {}
    } {}
    do_test corruptC-3.$tn.($qseed).$i.10 {
      catchsql {BEGIN; CREATE TABLE t3 AS SELECT x,3 as y FROM t2 WHERE rowid%5!=0; ROLLBACK;}
      set x {}
    } {}

    # check the integrity of the database.
    # once the corruption is detected, we can stop.
    ifcapable {integrityck} {
      set res [ catchsql {PRAGMA integrity_check} ]
      set ans [lindex $res 1]
................................................................................
      }
    }

    # Check that no page references were leaked.
    # TBD:  need to figure out why this doesn't work
    # work with ROLLBACKs...
    if {0} {
      do_test corruptC-3.$tn.($qseed).$i.11 {
        set bt [btree_from_db db]
        db_enter db
        array set stats [btree_pager_stats $bt]
        db_leave db
        set stats(ref)
      } {0}
    }

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file is the driver for the "soak" tests. It is a peer of the
# quick.test and all.test scripts.
#
# $Id: soak.test,v 1.3 2008/07/12 14:52:20 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
rename finish_test really_finish_test
proc finish_test {} {}

# By default, guarantee that the tests will run for at least 1 hour.
................................................................................
#
# The general principle is to run those SQLite tests that use
# pseudo-random data in some way over and over again for a very 
# long time. The number of tests run depends on the value of 
# global variable $TIMEOUT - tests are run for at least $TIMEOUT 
# seconds.
#
#   fuzz.test   (pseudo-random SQL statements)
#   trans.test  (pseudo-random changes to a database followed by rollbacks)
#
# fuzzy malloc?
#
# Many database changes maintaining some kind of invariant. 
# Storing checksums etc.
#

# List of test files that are run by this file.
#
set SOAKTESTS {
  fuzz.test
  fuzz_malloc.test
  trans.test

}

set ISQUICK 1

set soak_starttime  [clock seconds]
set soak_finishtime [expr {$soak_starttime + $TIMEOUT}]

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file is the driver for the "soak" tests. It is a peer of the
# quick.test and all.test scripts.
#
# $Id: soak.test,v 1.4 2008/11/13 18:29:51 shane Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
rename finish_test really_finish_test
proc finish_test {} {}

# By default, guarantee that the tests will run for at least 1 hour.
................................................................................
#
# The general principle is to run those SQLite tests that use
# pseudo-random data in some way over and over again for a very 
# long time. The number of tests run depends on the value of 
# global variable $TIMEOUT - tests are run for at least $TIMEOUT 
# seconds.
#
#   fuzz.test     (pseudo-random SQL statements)
#   trans.test    (pseudo-random changes to a database followed by rollbacks)
#   fuzz_malloc.test
#   corruptC.test (pseudo-random corruption to a database)
#
# Many database changes maintaining some kind of invariant. 
# Storing checksums etc.
#

# List of test files that are run by this file.
#
set SOAKTESTS {
  fuzz.test
  fuzz_malloc.test
  trans.test
  corruptC.test
}

set ISQUICK 1

set soak_starttime  [clock seconds]
set soak_finishtime [expr {$soak_starttime + $TIMEOUT}]