** 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 1.353 2007/04/07 15:03:17 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................
      put4byte(&pPage->aData[4], 0);
      put4byte(&pPage1->aData[32], pPage->pgno);
      TRACE(("FREE-PAGE: %d new trunk page replacing %d\n",
              pPage->pgno, pTrunk->pgno));
    }else{
      /* Add the newly freed page as a leaf on the current trunk */
      rc = sqlite3PagerWrite(pTrunk->pDbPage);
      if( rc ) return rc;
      put4byte(&pTrunk->aData[4], k+1);
      put4byte(&pTrunk->aData[8+k*4], pPage->pgno);
#ifndef SQLITE_SECURE_DELETE
      sqlite3PagerDontWrite(pBt->pPager, pPage->pgno);
#endif

      TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno));
    }
    releasePage(pTrunk);
  }
  return rc;
}

................................................................................
  for(i=0; i<k; i++){
    MemPage *pNew;
    if( i<nOld ){
      pNew = apNew[i] = apOld[i];
      pgnoNew[i] = pgnoOld[i];
      apOld[i] = 0;
      rc = sqlite3PagerWrite(pNew->pDbPage);

      if( rc ) goto balance_cleanup;
    }else{
      assert( i>0 );
      rc = allocateBtreePage(pBt, &pNew, &pgnoNew[i], pgnoNew[i-1], 0);
      if( rc ) goto balance_cleanup;
      apNew[i] = pNew;
    }
    nNew++;

    zeroPage(pNew, pageFlags);
  }

  /* Free any old pages that were not reused as new pages.
  */
  while( i<nOld ){
    rc = freePage(apOld[i]);
................................................................................
                 ** initialized before use.  Adding an extra initialization
                 ** to silence the compiler slows down the code. */
    int notUsed;
    unsigned char *tempCell = 0;
    assert( !pPage->leafData );
    getTempCursor(pCur, &leafCur);
    rc = sqlite3BtreeNext(&leafCur, &notUsed);
    if( rc!=SQLITE_OK ){
      if( rc!=SQLITE_NOMEM ){
        rc = SQLITE_CORRUPT_BKPT; 
      }
    }
    if( rc==SQLITE_OK ){
      rc = sqlite3PagerWrite(leafCur.pPage->pDbPage);
    }
    if( rc==SQLITE_OK ){
      TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
         pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
      dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));

** 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 1.354 2007/04/09 12:45:03 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.
................................................................................
      put4byte(&pPage->aData[4], 0);
      put4byte(&pPage1->aData[32], pPage->pgno);
      TRACE(("FREE-PAGE: %d new trunk page replacing %d\n",
              pPage->pgno, pTrunk->pgno));
    }else{
      /* Add the newly freed page as a leaf on the current trunk */
      rc = sqlite3PagerWrite(pTrunk->pDbPage);
      if( rc==SQLITE_OK ){
        put4byte(&pTrunk->aData[4], k+1);
        put4byte(&pTrunk->aData[8+k*4], pPage->pgno);
#ifndef SQLITE_SECURE_DELETE
        sqlite3PagerDontWrite(pBt->pPager, pPage->pgno);
#endif
      }
      TRACE(("FREE-PAGE: %d leaf on trunk page %d\n",pPage->pgno,pTrunk->pgno));
    }
    releasePage(pTrunk);
  }
  return rc;
}

................................................................................
  for(i=0; i<k; i++){
    MemPage *pNew;
    if( i<nOld ){
      pNew = apNew[i] = apOld[i];
      pgnoNew[i] = pgnoOld[i];
      apOld[i] = 0;
      rc = sqlite3PagerWrite(pNew->pDbPage);
      nNew++;
      if( rc ) goto balance_cleanup;
    }else{
      assert( i>0 );
      rc = allocateBtreePage(pBt, &pNew, &pgnoNew[i], pgnoNew[i-1], 0);
      if( rc ) goto balance_cleanup;
      apNew[i] = pNew;

      nNew++;
    }
    zeroPage(pNew, pageFlags);
  }

  /* Free any old pages that were not reused as new pages.
  */
  while( i<nOld ){
    rc = freePage(apOld[i]);
................................................................................
                 ** initialized before use.  Adding an extra initialization
                 ** to silence the compiler slows down the code. */
    int notUsed;
    unsigned char *tempCell = 0;
    assert( !pPage->leafData );
    getTempCursor(pCur, &leafCur);
    rc = sqlite3BtreeNext(&leafCur, &notUsed);





    if( rc==SQLITE_OK ){
      rc = sqlite3PagerWrite(leafCur.pPage->pDbPage);
    }
    if( rc==SQLITE_OK ){
      TRACE(("DELETE: table=%d delete internal from %d replace from leaf %d\n",
         pCur->pgnoRoot, pPage->pgno, leafCur.pPage->pgno));
      dropCell(pPage, pCur->idx, cellSizePtr(pPage, pCell));

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.235 2007/04/06 21:42:22 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  return TCL_OK;
}


/*
** Usage:   sqlite3_pager_refcounts  DB
**
** Return a list of numbers when are the PagerRefcount for each
** pager on each database.
*/
static int test_pager_refcounts(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
................................................................................
  sqlite3 *db;
  int i;
  int v, *a;
  Tcl_Obj *pResult;

  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " <STMT>", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  pResult = Tcl_NewObj();
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt==0 ){
      v = -1;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing all sorts of SQLite interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test1.c,v 1.236 2007/04/09 12:45:03 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
  return TCL_OK;
}


/*
** Usage:   sqlite3_pager_refcounts  DB
**
** Return a list of numbers which are the PagerRefcount for all
** pagers on each database connection.
*/
static int test_pager_refcounts(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
................................................................................
  sqlite3 *db;
  int i;
  int v, *a;
  Tcl_Obj *pResult;

  if( objc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"",
        Tcl_GetStringFromObj(objv[0], 0), " DB", 0);
    return TCL_ERROR;
  }
  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  pResult = Tcl_NewObj();
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt==0 ){
      v = -1;

# This file implements regression tests for SQLite library.  The
# focus of this file is testing for correct handling of I/O errors
# such as writes failing because the disk is full.
# 
# The tests in this file use special facilities that are only
# available in the SQLite test fixture.
#
# $Id: ioerr2.test,v 1.2 2007/04/09 11:20:54 danielk1977 Exp $

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

do_test ioerr2-1.1 {
  execsql {
    PRAGMA cache_size = 10;
................................................................................
  # pager must be in error state. In this case open a new database
  # connection. Otherwise, try a ROLLBACK, in case a transaction 
  # is still active.
  set rc [catch {execsql {PRAGMA integrity_check}} msg]
  if {$rc && $msg eq "disk I/O error"} {
    db close
    sqlite3 db test.db

  } else {
    if {$rc || $msg ne "ok"} {
      error $msg
    }
    catch {execsql ROLLBACK}
  }

  # Check that the database checksum is still $::cksum, and that
  # the integrity-check passes.
  set ck [execsql {SELECT md5sum(a, b) FROM t1}]
  do_test ${testname}.cksum [list set ck $ck] $::cksum
  integrity_check ${testname}.integrity



}

check_db ioerr2-2

set sql {
  PRAGMA cache_size = 10;
  PRAGMA default_cache_size = 10;

# This file implements regression tests for SQLite library.  The
# focus of this file is testing for correct handling of I/O errors
# such as writes failing because the disk is full.
# 
# The tests in this file use special facilities that are only
# available in the SQLite test fixture.
#
# $Id: ioerr2.test,v 1.3 2007/04/09 12:45:03 drh Exp $

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

do_test ioerr2-1.1 {
  execsql {
    PRAGMA cache_size = 10;
................................................................................
  # pager must be in error state. In this case open a new database
  # connection. Otherwise, try a ROLLBACK, in case a transaction 
  # is still active.
  set rc [catch {execsql {PRAGMA integrity_check}} msg]
  if {$rc && $msg eq "disk I/O error"} {
    db close
    sqlite3 db test.db
    set refcnt 0
  } else {
    if {$rc || $msg ne "ok"} {
      error $msg
    }
    catch {execsql ROLLBACK}
  }

  # Check that the database checksum is still $::cksum, and that
  # the integrity-check passes.
  set ck [execsql {SELECT md5sum(a, b) FROM t1}]
  do_test ${testname}.cksum [list set ck $ck] $::cksum
  integrity_check ${testname}.integrity
  do_test ${testname}.refcnt {
    lindex [sqlite3_pager_refcounts db] 0
  } 0
}

check_db ioerr2-2

set sql {
  PRAGMA cache_size = 10;
  PRAGMA default_cache_size = 10;