SQLite

  assert( pPager->pWal );
#ifdef SQLITE_DEBUG
  /* Verify that the page list is in accending order */
  for(p=pList; p && p->pDirty; p=p->pDirty){
    assert( p->pgno < p->pDirty->pgno );
  }
#endif

  if( isCommit ){
    /* If a WAL transaction is being committed, there is no point in writing
    ** any pages with page numbers greater than nTruncate into the WAL file.
    ** They will never be read by any client. So remove them from the pDirty
    ** list here. */
    PgHdr *p;
    PgHdr **ppNext = &pList;
    for(p=pList; (*ppNext = p); p=p->pDirty){
      if( p->pgno<=nTruncate ) ppNext = &p->pDirty;
    }
    assert( pList );
  }

  if( pList->pgno==1 ) pager_write_changecounter(pList);
  rc = sqlite3WalFrames(pPager->pWal, 
      pPager->pageSize, pList, nTruncate, isCommit, syncFlags
  );
  if( rc==SQLITE_OK && pPager->pBackup ){
    PgHdr *p;
    for(p=pList; p; p=p->pDirty){
      sqlite3BackupUpdate(pPager->pBackup, p->pgno, (u8 *)p->pData);
    }
  }

#ifdef SQLITE_CHECK_PAGES
  pList = sqlite3PcacheDirtyList(pPager->pPCache);
  for(p=pList; p; p=p->pDirty){
    pager_set_pagehash(p);
  }
#endif

  return rc;
}

#

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

set testprefix wal

ifcapable !wal {finish_test ; return }

proc reopen_db {} {
  catch { db close }
  file delete -force test.db test.db-wal test.db-wal-summary
  sqlite3_wal db test.db

  execsql { SELECT * FROM t1 }
} {1 2 3 4}
set nPage [expr 2+$AUTOVACUUM]
do_test wal-23.4 { 
  set ::log 
} [list SQLITE_OK "Recovered $nPage frames from WAL file $walfile"]


ifcapable autovacuum {
  # This block tests that if the size of a database is reduced by a 
  # transaction (because of an incremental or auto-vacuum), that no
  # data is written to the WAL file for the truncated pages as part
  # of the commit. e.g. if a transaction reduces the size of a database
  # to N pages, data for page N+1 should not be written to the WAL file 
  # when committing the transaction. At one point such data was being 
  # written.
  #
  catch {db close}
  forcedelete test.db
  sqlite3 db test.db
  do_execsql_test 24.1 {
    PRAGMA auto_vacuum = 2;
    PRAGMA journal_mode = WAL;
    PRAGMA page_size = 1024;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(randomblob(5000));
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
    INSERT INTO t1 SELECT * FROM t1;
  } {wal}
  do_execsql_test 24.2 { 
    DELETE FROM t1;
    PRAGMA wal_checkpoint;
  } {0 109 109}
  do_test 24.3 {
    db close
    sqlite3 db test.db
    file exists test.db-wal
  } 0
  do_test 24.4 {
    file size test.db
  } [expr 84 * 1024]
  do_test 24.5 {
    execsql { 
      PRAGMA incremental_vacuum;
      PRAGMA wal_checkpoint;
    }
    file size test.db
  } [expr 3 * 1024]
  do_test 24.6 {
    file size test.db-wal
  } 2128
}

db close
sqlite3_shutdown
test_sqlite3_log
sqlite3_initialize

finish_test