** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.317 2007/04/05 05:46:14 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>
................................................................................
    assert(pPager->nRef>0 || pgno==1);
    if( pgno>sqlite3PagerPagecount(pPager) ){
      /* This can happen after a truncation in exclusive mode. The pager
      ** cache contains pages that are located after the end of the 
      ** database file. Zero such pages before returning. Not doing this 
      ** was causing the problem reported in ticket #2285.
      */






      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
    }
    TEST_INCR(pPager->nHit);
    page_ref(pPg);
  }
  *ppPage = pPg;
  return SQLITE_OK;

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.318 2007/04/05 08:40:32 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>
................................................................................
    assert(pPager->nRef>0 || pgno==1);
    if( pgno>sqlite3PagerPagecount(pPager) ){
      /* This can happen after a truncation in exclusive mode. The pager
      ** cache contains pages that are located after the end of the 
      ** database file. Zero such pages before returning. Not doing this 
      ** was causing the problem reported in ticket #2285.
      */
      if( pPager->errCode ){
        /* This case catches an IO error in sqlite3PagerPagecount(). If
        ** the error occured, PagerPagecount() returned 0.
        */
        return pPager->errCode;
      }
      memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
    }
    TEST_INCR(pPager->nHit);
    page_ref(pPg);
  }
  *ppPage = pPg;
  return SQLITE_OK;