}
}

/*
** Map the wal-index file into memory if it isn't already. 
**
** The reqSize parameter is the minimum required size of the mapping.
** A value of -1 means "don't care".  The reqSize parameter is ignored
** if the mapping is already held.
*/
static int walIndexMap(Wal *pWal, int reqSize){
  int rc = SQLITE_OK;
  if( pWal->pWiData==0 ){
    rc = pWal->pVfs->xShmGet(pWal->pVfs, pWal->pWIndex, reqSize,
                             &pWal->szWIndex, (void**)(char*)&pWal->pWiData);
    if( rc==SQLITE_OK && pWal->pWiData==0 ){
      /* Make sure pWal->pWiData is not NULL while we are holding the
      ** lock on the mapping. */
      assert( pWal->szWIndex==0 );
      pWal->pWiData = &pWal->iCallback;

  }
}

/*
** Map the wal-index file into memory if it isn't already. 
**
** The reqSize parameter is the minimum required size of the mapping.
** A value of -1 means "don't care".

*/
static int walIndexMap(Wal *pWal, int reqSize){
  int rc = SQLITE_OK;
  if( pWal->pWiData==0 || reqSize>pWal->szWIndex ){
    rc = pWal->pVfs->xShmGet(pWal->pVfs, pWal->pWIndex, reqSize,
                             &pWal->szWIndex, (void**)(char*)&pWal->pWiData);
    if( rc==SQLITE_OK && pWal->pWiData==0 ){
      /* Make sure pWal->pWiData is not NULL while we are holding the
      ** lock on the mapping. */
      assert( pWal->szWIndex==0 );
      pWal->pWiData = &pWal->iCallback;

# wal-1.*: Read and write the database.
# wal-2.*: Test MVCC with one reader, one writer.
# wal-3.*: Test transaction rollback.
# wal-4.*: Test savepoint/statement rollback.
# wal-5.*: Test the temp database.
# wal-6.*: Test creating databases with different page sizes.
#


do_test wal-0.1 {
  execsql { PRAGMA synchronous = normal }
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test wal-0.2 {
  file size test.db
................................................................................
  # When the bug was present, the following was returning {1 2 3 4} only,
  # as [db2] had an out-of-date copy of the wal-index header when it was
  # closed.
  #
  sqlite3 db test.db
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6}
































































catch { db2 close }
catch { db close }

finish_test

# wal-1.*: Read and write the database.
# wal-2.*: Test MVCC with one reader, one writer.
# wal-3.*: Test transaction rollback.
# wal-4.*: Test savepoint/statement rollback.
# wal-5.*: Test the temp database.
# wal-6.*: Test creating databases with different page sizes.
#
#

do_test wal-0.1 {
  execsql { PRAGMA synchronous = normal }
  execsql { PRAGMA journal_mode = wal }
} {wal}
do_test wal-0.2 {
  file size test.db
................................................................................
  # When the bug was present, the following was returning {1 2 3 4} only,
  # as [db2] had an out-of-date copy of the wal-index header when it was
  # closed.
  #
  sqlite3 db test.db
  execsql { SELECT * FROM t1 }
} {1 2 3 4 5 6}

#-------------------------------------------------------------------------
# This test - wal-20.* - uses two connections. One in this process and
# the other in an external process. The procedure is:
#
#   1. Using connection 1, create the database schema.
#
#   2. Using connection 2 (in an external process), add so much
#      data to the database without checkpointing that a wal-index 
#      larger than 64KB is required.
#
#   3. Using connection 1, checkpoint the database. Make sure all
#      the data is present and the database is not corrupt.
#
# At one point, SQLite was failing to grow the mapping of the wal-index
# file in step 3 and the checkpoint was corrupting the database file.
#
do_test wal-20.1 {
  file delete -force test.db test.db-wal test.db-journal
  sqlite3 db test.db
  execsql {
    PRAGMA journal_mode = WAL;
    CREATE TABLE t1(x);
    INSERT INTO t1 VALUES(randomblob(900));
    SELECT count(*) FROM t1;
  }
} {wal 1}
do_test wal-20.2 {
  set ::buddy [launch_testfixture]
  testfixture $::buddy {
    sqlite3 db test.db
    db transaction { db eval {
      PRAGMA wal_autocheckpoint = 0;
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 2 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 4 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 8 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 16 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 32 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 64 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 128 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 256 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 512 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 1024 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 2048 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 4096 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 8192 */
      INSERT INTO t1 SELECT randomblob(900) FROM t1;       /* 16384 */
    } }
  }
} {0}
do_test wal-20.3 {
  close $::buddy
  execsql {
    PRAGMA wal_checkpoint;
    SELECT count(*) FROM t1;
  }
} {16384}
do_test wal-20.4 {
  db close
  sqlite3 db test.db
  execsql { SELECT count(*) FROM t1 }
} {16384}
integrity_check wal-20.5

catch { db2 close }
catch { db close }

finish_test