Imported Upstream version 2.0.3

1 files changed, 2467 insertions, 0 deletions

diff --git a/test/pager1.test b/test/pager1.test
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--- /dev/null
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@@ -0,0 +1,2467 @@
+# 2010 June 15
+#
+# The author disclaims copyright to this source code.  In place of
+# 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.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+source $testdir/malloc_common.tcl
+source $testdir/wal_common.tcl
+
+# Do not use a codec for tests in this file, as the database file is
+# manipulated directly using tcl scripts (using the [hexio_write] command).
+#
+do_not_use_codec
+
+#
+# pager1-1.*: Test inter-process locking (clients in multiple processes).
+#
+# pager1-2.*: Test intra-process locking (multiple clients in this process).
+#
+# pager1-3.*: Savepoint related tests.
+#
+# pager1-4.*: Hot-journal related tests.
+#
+# pager1-5.*: Cases related to multi-file commits.
+#
+# pager1-6.*: Cases related to "PRAGMA max_page_count"
+#
+# pager1-7.*: Cases specific to "PRAGMA journal_mode=TRUNCATE"
+#
+# pager1-8.*: Cases using temporary and in-memory databases.
+#
+# pager1-9.*: Tests related to the backup API.
+#
+# pager1-10.*: Test that the assumed file-system sector-size is limited to
+#              64KB.
+#
+# pager1-12.*: Tests involving "PRAGMA page_size"
+#
+# pager1-13.*: Cases specific to "PRAGMA journal_mode=PERSIST"
+#
+# pager1-14.*: Cases specific to "PRAGMA journal_mode=OFF"
+#
+# pager1-15.*: Varying sqlite3_vfs.szOsFile
+#
+# pager1-16.*: Varying sqlite3_vfs.mxPathname
+#
+# pager1-17.*: Tests related to "PRAGMA omit_readlock"
+#
+# pager1-18.*: Test that the pager layer responds correctly if the b-tree
+#              requests an invalid page number (due to db corruption).
+#
+
+proc recursive_select {id table {script {}}} {
+  set cnt 0
+  db eval "SELECT rowid, * FROM $table WHERE rowid = ($id-1)" {
+    recursive_select $rowid $table $script
+    incr cnt
+  }
+  if {$cnt==0} { eval $script }
+}
+
+set a_string_counter 1
+proc a_string {n} {
+  global a_string_counter
+  incr a_string_counter
+  string range [string repeat "${a_string_counter}." $n] 1 $n
+}
+db func a_string a_string
+
+do_multiclient_test tn {
+
+  # Create and populate a database table using connection [db]. Check 
+  # that connections [db2] and [db3] can see the schema and content.
+  #
+  do_test pager1-$tn.1 {
+    sql1 {
+      CREATE TABLE t1(a PRIMARY KEY, b);
+      CREATE INDEX i1 ON t1(b);
+      INSERT INTO t1 VALUES(1, 'one'); INSERT INTO t1 VALUES(2, 'two');
+    }
+  } {}
+  do_test pager1-$tn.2 { sql2 { SELECT * FROM t1 } } {1 one 2 two}
+  do_test pager1-$tn.3 { sql3 { SELECT * FROM t1 } } {1 one 2 two}
+
+  # Open a transaction and add a row using [db]. This puts [db] in
+  # RESERVED state. Check that connections [db2] and [db3] can still
+  # read the database content as it was before the transaction was
+  # opened. [db] should see the inserted row.
+  #
+  do_test pager1-$tn.4 {
+    sql1 {
+      BEGIN;
+        INSERT INTO t1 VALUES(3, 'three');
+    }
+  } {}
+  do_test pager1-$tn.5 { sql2 { SELECT * FROM t1 } } {1 one 2 two}
+  do_test pager1-$tn.7 { sql1 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+
+  # [db] still has an open write transaction. Check that this prevents
+  # other connections (specifically [db2]) from writing to the database.
+  #
+  # Even if [db2] opens a transaction first, it may not write to the
+  # database. After the attempt to write the db within a transaction, 
+  # [db2] is left with an open transaction, but not a read-lock on
+  # the main database. So it does not prevent [db] from committing.
+  #
+  do_test pager1-$tn.8 { 
+    csql2 { UPDATE t1 SET a = a + 10 }
+  } {1 {database is locked}}
+  do_test pager1-$tn.9 { 
+    csql2 { 
+      BEGIN;
+      UPDATE t1 SET a = a + 10;
+    }
+  } {1 {database is locked}}
+
+  # Have [db] commit its transactions. Check the other connections can
+  # now see the new database content.
+  #
+  do_test pager1-$tn.10 { sql1 { COMMIT } } {}
+  do_test pager1-$tn.11 { sql1 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+  do_test pager1-$tn.12 { sql2 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+  do_test pager1-$tn.13 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+
+  # Check that, as noted above, [db2] really did keep an open transaction
+  # after the attempt to write the database failed.
+  #
+  do_test pager1-$tn.14 { 
+    csql2 { BEGIN } 
+  } {1 {cannot start a transaction within a transaction}}
+  do_test pager1-$tn.15 { sql2 { ROLLBACK } } {}
+
+  # Have [db2] open a transaction and take a read-lock on the database.
+  # Check that this prevents [db] from writing to the database (outside
+  # of any transaction). After this fails, check that [db3] can read
+  # the db (showing that [db] did not take a PENDING lock etc.)
+  #
+  do_test pager1-$tn.15 { 
+    sql2 { BEGIN; SELECT * FROM t1; }
+  } {1 one 2 two 3 three}
+  do_test pager1-$tn.16 { 
+    csql1 { UPDATE t1 SET a = a + 10 }
+  } {1 {database is locked}}
+  do_test pager1-$tn.17 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+
+  # This time, have [db] open a transaction before writing the database.
+  # This works - [db] gets a RESERVED lock which does not conflict with
+  # the SHARED lock [db2] is holding.
+  #
+  do_test pager1-$tn.18 { 
+    sql1 { 
+      BEGIN;  
+      UPDATE t1 SET a = a + 10; 
+    }
+  } {}
+  do_test pager1-$tn-19 { 
+    sql1 { PRAGMA lock_status } 
+  } {main reserved temp closed}
+  do_test pager1-$tn-20 { 
+    sql2 { PRAGMA lock_status } 
+  } {main shared temp closed}
+
+  # Check that all connections can still read the database. Only [db] sees
+  # the updated content (as the transaction has not been committed yet).
+  #
+  do_test pager1-$tn.21 { sql1 { SELECT * FROM t1 } } {11 one 12 two 13 three}
+  do_test pager1-$tn.22 { sql2 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+  do_test pager1-$tn.23 { sql3 { SELECT * FROM t1 } } {1 one 2 two 3 three}
+
+  # Because [db2] still has the SHARED lock, [db] is unable to commit the
+  # transaction. If it tries, an error is returned and the connection 
+  # upgrades to a PENDING lock.
+  #
+  # Once this happens, [db] can read the database and see the new content,
+  # [db2] (still holding SHARED) can still read the old content, but [db3]
+  # (not holding any lock) is prevented by [db]'s PENDING from reading
+  # the database.
+  #
+  do_test pager1-$tn.24 { csql1 { COMMIT } } {1 {database is locked}}
+  do_test pager1-$tn-25 { 
+    sql1 { PRAGMA lock_status } 
+  } {main pending temp closed}
+  do_test pager1-$tn.26 { sql1 { SELECT * FROM t1  } } {11 one 12 two 13 three}
+  do_test pager1-$tn.27 { sql2 { SELECT * FROM t1  } } {1 one 2 two 3 three}
+  do_test pager1-$tn.28 { csql3 { SELECT * FROM t1 } } {1 {database is locked}}
+
+  # Have [db2] commit its read transaction, releasing the SHARED lock it
+  # is holding. Now, neither [db2] nor [db3] may read the database (as [db]
+  # is still holding a PENDING).
+  #
+  do_test pager1-$tn.29 { sql2 { COMMIT } } {}
+  do_test pager1-$tn.30 { csql2 { SELECT * FROM t1 } } {1 {database is locked}}
+  do_test pager1-$tn.31 { csql3 { SELECT * FROM t1 } } {1 {database is locked}}
+
+  # [db] is now able to commit the transaction. Once the transaction is 
+  # committed, all three connections can read the new content.
+  #
+  do_test pager1-$tn.25 { sql1 { UPDATE t1 SET a = a+10 } } {}
+  do_test pager1-$tn.26 { sql1 { COMMIT } } {}
+  do_test pager1-$tn.27 { sql1 { SELECT * FROM t1 } } {21 one 22 two 23 three}
+  do_test pager1-$tn.27 { sql2 { SELECT * FROM t1 } } {21 one 22 two 23 three}
+  do_test pager1-$tn.28 { sql3 { SELECT * FROM t1 } } {21 one 22 two 23 three}
+
+  # Install a busy-handler for connection [db].
+  #
+  set ::nbusy [list]
+  proc busy {n} {
+    lappend ::nbusy $n
+    if {$n>5} { sql2 COMMIT }
+    return 0
+  }
+  db busy busy
+
+  do_test pager1-$tn.29 { 
+    sql1 { BEGIN ; INSERT INTO t1 VALUES('x', 'y') } 
+  } {}
+  do_test pager1-$tn.30 { 
+    sql2 { BEGIN ; SELECT * FROM t1 } 
+  } {21 one 22 two 23 three}
+  do_test pager1-$tn.31 { sql1 COMMIT } {}
+  do_test pager1-$tn.32 { set ::nbusy } {0 1 2 3 4 5 6}
+}
+
+#-------------------------------------------------------------------------
+# Savepoint related test cases.
+#
+# pager1-3.1.2.*: Force a savepoint rollback to cause the database file
+#                 to grow.
+#
+# pager1-3.1.3.*: Use a journal created in synchronous=off mode as part
+#                 of a savepoint rollback.
+# 
+do_test pager1-3.1.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    CREATE TABLE counter(
+      i CHECK (i<5), 
+      u CHECK (u<10)
+    );
+    INSERT INTO counter VALUES(0, 0);
+    CREATE TRIGGER tr1 AFTER INSERT ON t1 BEGIN
+      UPDATE counter SET i = i+1;
+    END;
+    CREATE TRIGGER tr2 AFTER UPDATE ON t1 BEGIN
+      UPDATE counter SET u = u+1;
+    END;
+  }
+  execsql { SELECT * FROM counter }
+} {0 0}
+
+do_execsql_test pager1-3.1.2 {
+  PRAGMA cache_size = 10;
+  BEGIN;
+    INSERT INTO t1 VALUES(1, randomblob(1500));
+    INSERT INTO t1 VALUES(2, randomblob(1500));
+    INSERT INTO t1 VALUES(3, randomblob(1500));
+    SELECT * FROM counter;
+} {3 0}
+do_catchsql_test pager1-3.1.3 {
+    INSERT INTO t1 SELECT a+3, randomblob(1500) FROM t1
+} {1 {constraint failed}}
+do_execsql_test pager1-3.4 { SELECT * FROM counter } {3 0}
+do_execsql_test pager1-3.5 { SELECT a FROM t1 } {1 2 3}
+do_execsql_test pager1-3.6 { COMMIT } {}
+
+foreach {tn sql tcl} {
+  7  { PRAGMA synchronous = NORMAL ; PRAGMA temp_store = 0 } {
+    testvfs tv -default 1
+    tv devchar safe_append
+  }
+  8  { PRAGMA synchronous = NORMAL ; PRAGMA temp_store = 2 } {
+    testvfs tv -default 1
+    tv devchar sequential
+  }
+  9  { PRAGMA synchronous = FULL } { }
+  10 { PRAGMA synchronous = NORMAL } { }
+  11 { PRAGMA synchronous = OFF } { }
+  12 { PRAGMA synchronous = FULL ; PRAGMA fullfsync = 1 } { }
+  13 { PRAGMA synchronous = FULL } {
+    testvfs tv -default 1
+    tv devchar sequential
+  }
+  14 { PRAGMA locking_mode = EXCLUSIVE } {
+  }
+} {
+  do_test pager1-3.$tn.1 {
+    eval $tcl
+    faultsim_delete_and_reopen
+    db func a_string a_string
+    execsql $sql
+    execsql {
+      PRAGMA auto_vacuum = 2;
+      PRAGMA cache_size = 10;
+      CREATE TABLE z(x INTEGER PRIMARY KEY, y);
+      BEGIN;
+        INSERT INTO z VALUES(NULL, a_string(800));
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   2
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   4
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --   8
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  16
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  32
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     --  64
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     -- 128
+        INSERT INTO z SELECT NULL, a_string(800) FROM z;     -- 256
+      COMMIT;
+    }
+    execsql { PRAGMA auto_vacuum }
+  } {2}
+  do_execsql_test pager1-3.$tn.2 {
+    BEGIN;
+      INSERT INTO z VALUES(NULL, a_string(800));
+      INSERT INTO z VALUES(NULL, a_string(800));
+      SAVEPOINT one;
+        UPDATE z SET y = NULL WHERE x>256;
+        PRAGMA incremental_vacuum;
+        SELECT count(*) FROM z WHERE x < 100;
+      ROLLBACK TO one;
+    COMMIT;
+  } {99}
+
+  do_execsql_test pager1-3.$tn.3 {
+    BEGIN;
+      SAVEPOINT one;
+        UPDATE z SET y = y||x;
+      ROLLBACK TO one;
+    COMMIT;
+    SELECT count(*) FROM z;
+  } {258}
+
+  do_execsql_test pager1-3.$tn.4 {
+    SAVEPOINT one;
+      UPDATE z SET y = y||x;
+    ROLLBACK TO one;
+  } {}
+  do_execsql_test pager1-3.$tn.5 {
+    SELECT count(*) FROM z;
+    RELEASE one;
+    PRAGMA integrity_check;
+  } {258 ok}
+
+  do_execsql_test pager1-3.$tn.6 {
+    SAVEPOINT one;
+    RELEASE one;
+  } {}
+
+  db close
+  catch { tv delete }
+}
+
+#-------------------------------------------------------------------------
+# Hot journal rollback related test cases.
+#
+# pager1.4.1.*: Test that the pager module deletes very small invalid
+#               journal files.
+#
+# pager1.4.2.*: Test that if the master journal pointer at the end of a
+#               hot-journal file appears to be corrupt (checksum does not
+#               compute) the associated journal is rolled back (and no
+#               xAccess() call to check for the presence of any master 
+#               journal file is made).
+#
+# pager1.4.3.*: Test that the contents of a hot-journal are ignored if the
+#               page-size or sector-size in the journal header appear to
+#               be invalid (too large, too small or not a power of 2).
+#
+# pager1.4.4.*: Test hot-journal rollback of journal file with a master
+#               journal pointer generated in various "PRAGMA synchronous"
+#               modes.
+#
+# pager1.4.5.*: Test that hot-journal rollback stops if it encounters a
+#               journal-record for which the checksum fails.
+#
+# pager1.4.6.*: Test that when rolling back a hot-journal that contains a
+#               master journal pointer, the master journal file is deleted
+#               after all the hot-journals that refer to it are deleted.
+#
+# pager1.4.7.*: Test that if a hot-journal file exists but a client can
+#               open it for reading only, the database cannot be accessed and
+#               SQLITE_CANTOPEN is returned.
+# 
+do_test pager1.4.1.1 {
+  faultsim_delete_and_reopen
+  execsql { 
+    CREATE TABLE x(y, z);
+    INSERT INTO x VALUES(1, 2);
+  }
+  set fd [open test.db-journal w]
+  puts -nonewline $fd "helloworld"
+  close $fd
+  file exists test.db-journal
+} {1}
+do_test pager1.4.1.2 { execsql { SELECT * FROM x } } {1 2}
+do_test pager1.4.1.3 { file exists test.db-journal } {0}
+
+# Set up a [testvfs] to snapshot the file-system just before SQLite
+# deletes the master-journal to commit a multi-file transaction.
+#
+# In subsequent test cases, invoking [faultsim_restore_and_reopen] sets
+# up the file system to contain two databases, two hot-journal files and
+# a master-journal.
+#
+do_test pager1.4.2.1 {
+  testvfs tstvfs -default 1
+  tstvfs filter xDelete
+  tstvfs script xDeleteCallback
+  proc xDeleteCallback {method file args} {
+    set file [file tail $file]
+    if { [string match *mj* $file] } { faultsim_save }
+  }
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql {
+    ATTACH 'test.db2' AS aux;
+    PRAGMA journal_mode = DELETE;
+    PRAGMA main.cache_size = 10;
+    PRAGMA aux.cache_size = 10;
+    CREATE TABLE t1(a UNIQUE, b UNIQUE);
+    CREATE TABLE aux.t2(a UNIQUE, b UNIQUE);
+    INSERT INTO t1 VALUES(a_string(200), a_string(300));
+    INSERT INTO t1 SELECT a_string(200), a_string(300) FROM t1;
+    INSERT INTO t1 SELECT a_string(200), a_string(300) FROM t1;
+    INSERT INTO t2 SELECT * FROM t1;
+    BEGIN;
+      INSERT INTO t1 SELECT a_string(201), a_string(301) FROM t1;
+      INSERT INTO t1 SELECT a_string(202), a_string(302) FROM t1;
+      INSERT INTO t1 SELECT a_string(203), a_string(303) FROM t1;
+      INSERT INTO t1 SELECT a_string(204), a_string(304) FROM t1;
+      REPLACE INTO t2 SELECT * FROM t1;
+    COMMIT;
+  }
+  db close
+  tstvfs delete
+} {}
+
+if {$::tcl_platform(platform)!="windows"} {
+do_test pager1.4.2.2 {
+  faultsim_restore_and_reopen
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  }
+} {4 ok}
+do_test pager1.4.2.3 {
+  faultsim_restore_and_reopen
+  foreach f [glob test.db-mj*] { forcedelete $f }
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  }
+} {64 ok}
+do_test pager1.4.2.4 {
+  faultsim_restore_and_reopen
+  hexio_write test.db-journal [expr [file size test.db-journal]-20] 123456
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  }
+} {4 ok}
+do_test pager1.4.2.5 {
+  faultsim_restore_and_reopen
+  hexio_write test.db-journal [expr [file size test.db-journal]-20] 123456
+  foreach f [glob test.db-mj*] { forcedelete $f }
+  execsql {
+    SELECT count(*) FROM t1;
+    PRAGMA integrity_check;
+  }
+} {4 ok}
+}
+
+do_test pager1.4.3.1 {
+  testvfs tstvfs -default 1
+  tstvfs filter xSync
+  tstvfs script xSyncCallback
+  proc xSyncCallback {method file args} {
+    set file [file tail $file]
+    if { 0==[string match *journal $file] } { faultsim_save }
+  }
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA journal_mode = DELETE;
+    CREATE TABLE t1(a, b);
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+  }
+  db close
+  tstvfs delete
+} {}
+
+foreach {tn ofst value result} {
+          2   20    31       {1 2 3 4}
+          3   20    32       {1 2 3 4}
+          4   20    33       {1 2 3 4}
+          5   20    65536    {1 2 3 4}
+          6   20    131072   {1 2 3 4}
+
+          7   24    511      {1 2 3 4}
+          8   24    513      {1 2 3 4}
+          9   24    131072   {1 2 3 4}
+
+         10   32    65536    {1 2}
+} {
+  do_test pager1.4.3.$tn {
+    faultsim_restore_and_reopen
+    hexio_write test.db-journal $ofst [format %.8x $value]
+    execsql { SELECT * FROM t1 }
+  } $result
+}
+db close
+
+# Set up a VFS that snapshots the file-system just before a master journal
+# file is deleted to commit a multi-file transaction. Specifically, the
+# file-system is saved just before the xDelete() call to remove the 
+# master journal file from the file-system.
+#
+testvfs tv -default 1
+tv script copy_on_mj_delete
+set ::mj_filename_length 0
+proc copy_on_mj_delete {method filename args} {
+  if {[string match *mj* [file tail $filename]]} { 
+    set ::mj_filename_length [string length $filename]
+    faultsim_save 
+  }
+  return SQLITE_OK
+}
+
+set pwd [pwd]
+foreach {tn1 tcl} {
+  1 { set prefix "test.db" }
+  2 { 
+    # This test depends on the underlying VFS being able to open paths
+    # 512 bytes in length. The idea is to create a hot-journal file that
+    # contains a master-journal pointer so large that it could contain
+    # a valid page record (if the file page-size is 512 bytes). So as to
+    # make sure SQLite doesn't get confused by this.
+    #
+    set nPadding [expr 511 - $::mj_filename_length]
+    if {$tcl_platform(platform)=="windows"} {
+      # TBD need to figure out how to do this correctly for Windows!!!
+      set nPadding [expr 255 - $::mj_filename_length]
+    }
+
+    # We cannot just create a really long database file name to open, as
+    # Linux limits a single component of a path to 255 bytes by default
+    # (and presumably other systems have limits too). So create a directory
+    # hierarchy to work in.
+    #
+    set dirname "d123456789012345678901234567890/"
+    set nDir [expr $nPadding / 32]
+    if { $nDir } {
+      set p [string repeat $dirname $nDir]
+      file mkdir $p
+      cd $p
+    }
+
+    set padding [string repeat x [expr $nPadding %32]]
+    set prefix "test.db${padding}"
+  }
+} {
+  eval $tcl
+  foreach {tn2 sql} {
+    o { 
+      PRAGMA main.synchronous=OFF;
+      PRAGMA aux.synchronous=OFF;
+      PRAGMA journal_mode = DELETE;
+    }
+    o512 { 
+      PRAGMA main.synchronous=OFF;
+      PRAGMA aux.synchronous=OFF;
+      PRAGMA main.page_size = 512;
+      PRAGMA aux.page_size = 512;
+      PRAGMA journal_mode = DELETE;
+    }
+    n { 
+      PRAGMA main.synchronous=NORMAL;
+      PRAGMA aux.synchronous=NORMAL;
+      PRAGMA journal_mode = DELETE;
+    }
+    f { 
+      PRAGMA main.synchronous=FULL;
+      PRAGMA aux.synchronous=FULL;
+      PRAGMA journal_mode = DELETE;
+    }
+  } {
+
+    set tn "${tn1}.${tn2}"
+  
+    # Set up a connection to have two databases, test.db (main) and 
+    # test.db2 (aux). Then run a multi-file transaction on them. The
+    # VFS will snapshot the file-system just before the master-journal
+    # file is deleted to commit the transaction.
+    #
+    tv filter xDelete
+    do_test pager1-4.4.$tn.1 {
+      faultsim_delete_and_reopen $prefix
+      execsql "
+        ATTACH '${prefix}2' AS aux;
+        $sql
+        CREATE TABLE a(x);
+        CREATE TABLE aux.b(x);
+        INSERT INTO a VALUES('double-you');
+        INSERT INTO a VALUES('why');
+        INSERT INTO a VALUES('zed');
+        INSERT INTO b VALUES('won');
+        INSERT INTO b VALUES('too');
+        INSERT INTO b VALUES('free');
+      "
+      execsql {
+        BEGIN;
+          INSERT INTO a SELECT * FROM b WHERE rowid<=3;
+          INSERT INTO b SELECT * FROM a WHERE rowid<=3;
+        COMMIT;
+      }
+    } {}
+    tv filter {}
+    
+    # Check that the transaction was committed successfully.
+    #
+    do_execsql_test pager1-4.4.$tn.2 {
+      SELECT * FROM a
+    } {double-you why zed won too free}
+    do_execsql_test pager1-4.4.$tn.3 {
+      SELECT * FROM b
+    } {won too free double-you why zed}
+    
+    # Restore the file-system and reopen the databases. Check that it now
+    # appears that the transaction was not committed (because the file-system
+    # was restored to the state where it had not been).
+    #
+    do_test pager1-4.4.$tn.4 {
+      faultsim_restore_and_reopen $prefix
+      execsql "ATTACH '${prefix}2' AS aux"
+    } {}
+    do_execsql_test pager1-4.4.$tn.5 {SELECT * FROM a} {double-you why zed}
+    do_execsql_test pager1-4.4.$tn.6 {SELECT * FROM b} {won too free}
+    
+    # Restore the file-system again. This time, before reopening the databases,
+    # delete the master-journal file from the file-system. It now appears that
+    # the transaction was committed (no master-journal file == no rollback).
+    #
+    do_test pager1-4.4.$tn.7 {
+      faultsim_restore_and_reopen $prefix
+      foreach f [glob ${prefix}-mj*] { forcedelete $f }
+      execsql "ATTACH '${prefix}2' AS aux"
+    } {}
+    do_execsql_test pager1-4.4.$tn.8 {
+      SELECT * FROM a
+    } {double-you why zed won too free}
+    do_execsql_test pager1-4.4.$tn.9 {
+      SELECT * FROM b
+    } {won too free double-you why zed}
+  }
+
+  cd $pwd
+}
+db close
+tv delete
+forcedelete $dirname
+
+
+# Set up a VFS to make a copy of the file-system just before deleting a
+# journal file to commit a transaction. The transaction modifies exactly
+# two database pages (and page 1 - the change counter).
+#
+testvfs tv -default 1
+tv sectorsize 512
+tv script copy_on_journal_delete
+tv filter xDelete
+proc copy_on_journal_delete {method filename args} {
+  if {[string match *journal $filename]} faultsim_save 
+  return SQLITE_OK
+}
+faultsim_delete_and_reopen
+do_execsql_test pager1.4.5.1 {
+  PRAGMA journal_mode = DELETE;
+  PRAGMA page_size = 1024;
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(a, b);
+  INSERT INTO t1 VALUES('I', 'II');
+  INSERT INTO t2 VALUES('III', 'IV');
+  BEGIN;
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t2 VALUES(3, 4);
+  COMMIT;
+} {delete}
+tv filter {}
+
+# Check the transaction was committed:
+#
+do_execsql_test pager1.4.5.2 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {I II 1 2 III IV 3 4}
+
+# Now try four tests:
+#
+#  pager1-4.5.3: Restore the file-system. Check that the whole transaction 
+#                is rolled back.
+#
+#  pager1-4.5.4: Restore the file-system. Corrupt the first record in the
+#                journal. Check the transaction is not rolled back.
+#
+#  pager1-4.5.5: Restore the file-system. Corrupt the second record in the
+#                journal. Check that the first record in the transaction is 
+#                played back, but not the second.
+#
+#  pager1-4.5.6: Restore the file-system. Try to open the database with a
+#                readonly connection. This should fail, as a read-only
+#                connection cannot roll back the database file.
+#
+faultsim_restore_and_reopen
+do_execsql_test pager1.4.5.3 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {I II III IV}
+faultsim_restore_and_reopen
+hexio_write test.db-journal [expr 512+4+1024 - 202] 0123456789ABCDEF
+do_execsql_test pager1.4.5.4 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {I II 1 2 III IV 3 4}
+faultsim_restore_and_reopen
+hexio_write test.db-journal [expr 512+4+1024+4+4+1024 - 202] 0123456789ABCDEF
+do_execsql_test pager1.4.5.5 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {I II III IV 3 4}
+
+faultsim_restore_and_reopen
+db close
+sqlite3 db test.db -readonly 1
+do_catchsql_test pager1.4.5.6 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {1 {disk I/O error}}
+db close
+
+# Snapshot the file-system just before multi-file commit. Save the name
+# of the master journal file in $::mj_filename.
+#
+tv script copy_on_mj_delete
+tv filter xDelete
+proc copy_on_mj_delete {method filename args} {
+  if {[string match *mj* [file tail $filename]]} { 
+    set ::mj_filename $filename
+    faultsim_save 
+  }
+  return SQLITE_OK
+}
+do_test pager1.4.6.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA journal_mode = DELETE;
+    ATTACH 'test.db2' AS two;
+    CREATE TABLE t1(a, b);
+    CREATE TABLE two.t2(a, b);
+    INSERT INTO t1 VALUES(1, 't1.1');
+    INSERT INTO t2 VALUES(1, 't2.1');
+    BEGIN;
+      UPDATE t1 SET b = 't1.2';
+      UPDATE t2 SET b = 't2.2';
+    COMMIT;
+  }
+  tv filter {}
+  db close
+} {}
+
+faultsim_restore_and_reopen
+do_execsql_test pager1.4.6.2 { SELECT * FROM t1 }           {1 t1.1}
+do_test         pager1.4.6.3 { file exists $::mj_filename } {1}
+do_execsql_test pager1.4.6.4 {
+  ATTACH 'test.db2' AS two;
+  SELECT * FROM t2;
+} {1 t2.1}
+do_test pager1.4.6.5 { file exists $::mj_filename } {0}
+
+faultsim_restore_and_reopen
+db close
+do_test pager1.4.6.8 {
+  set ::mj_filename1 $::mj_filename
+  tv filter xDelete
+  sqlite3 db test.db2
+  execsql {
+    PRAGMA journal_mode = DELETE;
+    ATTACH 'test.db3' AS three;
+    CREATE TABLE three.t3(a, b);
+    INSERT INTO t3 VALUES(1, 't3.1');
+    BEGIN;
+      UPDATE t2 SET b = 't2.3';
+      UPDATE t3 SET b = 't3.3';
+    COMMIT;
+  }
+  expr {$::mj_filename1 != $::mj_filename}
+} {1}
+faultsim_restore_and_reopen
+tv filter {}
+
+# The file-system now contains:
+#
+#   * three databases
+#   * three hot-journal files
+#   * two master-journal files.
+#
+# The hot-journals associated with test.db2 and test.db3 point to
+# master journal $::mj_filename. The hot-journal file associated with
+# test.db points to master journal $::mj_filename1. So reading from
+# test.db should delete $::mj_filename1.
+#
+do_test pager1.4.6.9 {
+  lsort [glob test.db*]
+} [lsort [list                                           \
+  test.db test.db2 test.db3                              \
+  test.db-journal test.db2-journal test.db3-journal      \
+  [file tail $::mj_filename] [file tail $::mj_filename1]
+]]
+
+# The master-journal $::mj_filename1 contains pointers to test.db and 
+# test.db2. However the hot-journal associated with test.db2 points to
+# a different master-journal. Therefore, reading from test.db only should
+# be enough to cause SQLite to delete $::mj_filename1.
+#
+do_test         pager1.4.6.10 { file exists $::mj_filename  } {1}
+do_test         pager1.4.6.11 { file exists $::mj_filename1 } {1}
+do_execsql_test pager1.4.6.12 { SELECT * FROM t1 } {1 t1.1}
+do_test         pager1.4.6.13 { file exists $::mj_filename  } {1}
+do_test         pager1.4.6.14 { file exists $::mj_filename1 } {0}
+
+do_execsql_test pager1.4.6.12 {
+  ATTACH 'test.db2' AS two;
+  SELECT * FROM t2;
+} {1 t2.1}
+do_test         pager1.4.6.13 { file exists $::mj_filename }  {1}
+do_execsql_test pager1.4.6.14 {
+  ATTACH 'test.db3' AS three;
+  SELECT * FROM t3;
+} {1 t3.1}
+do_test         pager1.4.6.15 { file exists $::mj_filename }  {0}
+
+db close
+tv delete
+
+testvfs tv -default 1
+tv sectorsize 512
+tv script copy_on_journal_delete
+tv filter xDelete
+proc copy_on_journal_delete {method filename args} {
+  if {[string match *journal $filename]} faultsim_save 
+  return SQLITE_OK
+}
+faultsim_delete_and_reopen
+do_execsql_test pager1.4.7.1 {
+  PRAGMA journal_mode = DELETE;
+  CREATE TABLE t1(x PRIMARY KEY, y);
+  CREATE INDEX i1 ON t1(y);
+  INSERT INTO t1 VALUES('I',   'one');
+  INSERT INTO t1 VALUES('II',  'four');
+  INSERT INTO t1 VALUES('III', 'nine');
+  BEGIN;
+    INSERT INTO t1 VALUES('IV', 'sixteen');
+    INSERT INTO t1 VALUES('V' , 'twentyfive');
+  COMMIT;
+} {delete}
+tv filter {}
+db close
+tv delete 
+do_test pager1.4.7.2 {
+  faultsim_restore_and_reopen
+  catch {file attributes test.db-journal -permissions r--------}
+  catch {file attributes test.db-journal -readonly 1}
+  catchsql { SELECT * FROM t1 }
+} {1 {unable to open database file}}
+do_test pager1.4.7.3 {
+  db close
+  catch {file attributes test.db-journal -permissions rw-rw-rw-}
+  catch {file attributes test.db-journal -readonly 0}
+  delete_file test.db-journal
+  file exists test.db-journal
+} {0}
+
+#-------------------------------------------------------------------------
+# The following tests deal with multi-file commits.
+#
+# pager1-5.1.*: The case where a multi-file cannot be committed because
+#               another connection is holding a SHARED lock on one of the
+#               files. After the SHARED lock is removed, the COMMIT succeeds.
+#
+# pager1-5.2.*: Multi-file commits with journal_mode=memory.
+#
+# pager1-5.3.*: Multi-file commits with journal_mode=memory.
+#
+# pager1-5.4.*: Check that with synchronous=normal, the master-journal file
+#               name is added to a journal file immediately after the last
+#               journal record. But with synchronous=full, extra unused space
+#               is allocated between the last journal record and the 
+#               master-journal file name so that the master-journal file
+#               name does not lie on the same sector as the last journal file
+#               record.
+#
+# pager1-5.5.*: Check that in journal_mode=PERSIST mode, a journal file is
+#               truncated to zero bytes when a multi-file transaction is 
+#               committed (instead of the first couple of bytes being zeroed).
+#
+#
+do_test pager1-5.1.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    ATTACH 'test.db2' AS aux;
+    CREATE TABLE t1(a, b);
+    CREATE TABLE aux.t2(a, b);
+    INSERT INTO t1 VALUES(17, 'Lenin');
+    INSERT INTO t1 VALUES(22, 'Stalin');
+    INSERT INTO t1 VALUES(53, 'Khrushchev');
+  }
+} {}
+do_test pager1-5.1.2 {
+  execsql {
+    BEGIN;
+      INSERT INTO t1 VALUES(64, 'Brezhnev');
+      INSERT INTO t2 SELECT * FROM t1;
+  }
+  sqlite3 db2 test.db2
+  execsql {
+    BEGIN;
+      SELECT * FROM t2;
+  } db2
+} {}
+do_test pager1-5.1.3 {
+  catchsql COMMIT
+} {1 {database is locked}}
+do_test pager1-5.1.4 {
+  execsql COMMIT db2
+  execsql COMMIT
+  execsql { SELECT * FROM t2 } db2
+} {17 Lenin 22 Stalin 53 Khrushchev 64 Brezhnev}
+do_test pager1-5.1.5 {
+  db2 close
+} {}
+
+do_test pager1-5.2.1 {
+  execsql {
+    PRAGMA journal_mode = memory;
+    BEGIN;
+      INSERT INTO t1 VALUES(84, 'Andropov');
+      INSERT INTO t2 VALUES(84, 'Andropov');
+    COMMIT;
+  }
+} {memory}
+do_test pager1-5.3.1 {
+  execsql {
+    PRAGMA journal_mode = off;
+    BEGIN;
+      INSERT INTO t1 VALUES(85, 'Gorbachev');
+      INSERT INTO t2 VALUES(85, 'Gorbachev');
+    COMMIT;
+  }
+} {off}
+
+do_test pager1-5.4.1 {
+  db close
+  testvfs tv
+  sqlite3 db test.db -vfs tv
+  execsql { ATTACH 'test.db2' AS aux }
+
+  tv filter xDelete
+  tv script max_journal_size
+  tv sectorsize 512
+  set ::max_journal 0
+  proc max_journal_size {method args} {
+    set sz 0
+    catch { set sz [file size test.db-journal] }
+    if {$sz > $::max_journal} {
+      set ::max_journal $sz
+    }
+    return SQLITE_OK
+  }
+  execsql {
+    PRAGMA journal_mode = DELETE;
+    PRAGMA synchronous = NORMAL;
+    BEGIN;
+      INSERT INTO t1 VALUES(85, 'Gorbachev');
+      INSERT INTO t2 VALUES(85, 'Gorbachev');
+    COMMIT;
+  }
+  set ::max_journal
+} [expr 2615+[string length [pwd]]]
+do_test pager1-5.4.2 {
+  set ::max_journal 0
+  execsql {
+    PRAGMA synchronous = full;
+    BEGIN;
+      DELETE FROM t1 WHERE b = 'Lenin';
+      DELETE FROM t2 WHERE b = 'Lenin';
+    COMMIT;
+  }
+  set ::max_journal
+} [expr 3111+[string length [pwd]]]
+db close
+tv delete
+
+do_test pager1-5.5.1 {
+  sqlite3 db test.db
+  execsql { 
+    ATTACH 'test.db2' AS aux;
+    PRAGMA journal_mode = PERSIST;
+    CREATE TABLE t3(a, b);
+    INSERT INTO t3 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    UPDATE t3 SET b = randomblob(1500);
+  }
+  expr [file size test.db-journal] > 15000
+} {1}
+do_test pager1-5.5.2 {
+  execsql {
+    PRAGMA synchronous = full;
+    BEGIN;
+      DELETE FROM t1 WHERE b = 'Stalin';
+      DELETE FROM t2 WHERE b = 'Stalin';
+    COMMIT;
+  }
+  file size test.db-journal
+} {0}
+
+
+#-------------------------------------------------------------------------
+# The following tests work with "PRAGMA max_page_count"
+#
+do_test pager1-6.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA auto_vacuum = none;
+    PRAGMA max_page_count = 10;
+    CREATE TABLE t2(a, b);
+    CREATE TABLE t3(a, b);
+    CREATE TABLE t4(a, b);
+    CREATE TABLE t5(a, b);
+    CREATE TABLE t6(a, b);
+    CREATE TABLE t7(a, b);
+    CREATE TABLE t8(a, b);
+    CREATE TABLE t9(a, b);
+    CREATE TABLE t10(a, b);
+  }
+} {10}
+do_catchsql_test pager1-6.2 {
+  CREATE TABLE t11(a, b)
+} {1 {database or disk is full}}
+do_execsql_test pager1-6.4 { PRAGMA max_page_count      } {10}
+do_execsql_test pager1-6.5 { PRAGMA max_page_count = 15 } {15}
+do_execsql_test pager1-6.6 { CREATE TABLE t11(a, b)     } {}
+do_execsql_test pager1-6.7 {
+  BEGIN;
+    INSERT INTO t11 VALUES(1, 2);
+    PRAGMA max_page_count = 13;
+} {13}
+do_execsql_test pager1-6.8 {
+    INSERT INTO t11 VALUES(3, 4);
+    PRAGMA max_page_count = 10;
+} {11}
+do_execsql_test pager1-6.9 { COMMIT } {}
+
+do_execsql_test pager1-6.10 { PRAGMA max_page_count = 10 } {11}
+do_execsql_test pager1-6.11 { SELECT * FROM t11 }          {1 2 3 4}
+do_execsql_test pager1-6.12 { PRAGMA max_page_count }      {11}
+
+
+#-------------------------------------------------------------------------
+# The following tests work with "PRAGMA journal_mode=TRUNCATE" and
+# "PRAGMA locking_mode=EXCLUSIVE".
+#
+# Each test is specified with 5 variables. As follows:
+#
+#   $tn:  Test Number. Used as part of the [do_test] test names.
+#   $sql: SQL to execute.
+#   $res: Expected result of executing $sql.
+#   $js:  The expected size of the journal file, in bytes, after executing
+#         the SQL script. Or -1 if the journal is not expected to exist.
+#   $ws:  The expected size of the WAL file, in bytes, after executing
+#         the SQL script. Or -1 if the WAL is not expected to exist.
+#
+ifcapable wal {
+  faultsim_delete_and_reopen
+  foreach {tn sql res js ws} [subst {
+  
+    1  {
+      CREATE TABLE t1(a, b);
+      PRAGMA auto_vacuum=OFF;
+      PRAGMA synchronous=NORMAL;
+      PRAGMA page_size=1024;
+      PRAGMA locking_mode=EXCLUSIVE;
+      PRAGMA journal_mode=TRUNCATE;
+      INSERT INTO t1 VALUES(1, 2);
+    } {exclusive truncate} 0 -1
+  
+    2  {
+      BEGIN IMMEDIATE;
+        SELECT * FROM t1;
+      COMMIT;
+    } {1 2} 0 -1
+  
+    3  {
+      BEGIN;
+        SELECT * FROM t1;
+      COMMIT;
+    } {1 2} 0 -1
+  
+    4  { PRAGMA journal_mode = WAL }    wal       -1 -1
+    5  { INSERT INTO t1 VALUES(3, 4) }  {}        -1 [wal_file_size 1 1024]
+    6  { PRAGMA locking_mode = NORMAL } exclusive -1 [wal_file_size 1 1024]
+    7  { INSERT INTO t1 VALUES(5, 6); } {}        -1 [wal_file_size 2 1024]
+  
+    8  { PRAGMA journal_mode = TRUNCATE } truncate          0 -1
+    9  { INSERT INTO t1 VALUES(7, 8) }    {}                0 -1
+    10 { SELECT * FROM t1 }               {1 2 3 4 5 6 7 8} 0 -1
+  
+  }] {
+    do_execsql_test pager1-7.1.$tn.1 $sql $res
+    catch { set J -1 ; set J [file size test.db-journal] }
+    catch { set W -1 ; set W [file size test.db-wal] }
+    do_test pager1-7.1.$tn.2 { list $J $W } [list $js $ws]
+  }
+}
+
+do_test pager1-7.2.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA locking_mode = EXCLUSIVE;
+    CREATE TABLE t1(a, b);
+    BEGIN;
+      PRAGMA journal_mode = delete;
+      PRAGMA journal_mode = truncate;
+  }
+} {exclusive delete truncate}
+do_test pager1-7.2.2 {
+  execsql { INSERT INTO t1 VALUES(1, 2) }
+  execsql { PRAGMA journal_mode = persist }
+} {truncate}
+do_test pager1-7.2.3 {
+  execsql { COMMIT }
+  execsql {
+    PRAGMA journal_mode = persist;
+    PRAGMA journal_size_limit;
+  }
+} {persist -1}
+
+#-------------------------------------------------------------------------
+# The following tests, pager1-8.*, test that the special filenames 
+# ":memory:" and "" open temporary databases.
+#
+foreach {tn filename} {
+  1 :memory:
+  2 ""
+} {
+  do_test pager1-8.$tn.1 {
+    faultsim_delete_and_reopen
+    db close
+    sqlite3 db $filename
+    execsql {
+      PRAGMA auto_vacuum = 1;
+      CREATE TABLE x1(x);
+      INSERT INTO x1 VALUES('Charles');
+      INSERT INTO x1 VALUES('James');
+      INSERT INTO x1 VALUES('Mary');
+      SELECT * FROM x1;
+    }
+  } {Charles James Mary}
+
+  do_test pager1-8.$tn.2 {
+    sqlite3 db2 $filename
+    catchsql { SELECT * FROM x1 } db2
+  } {1 {no such table: x1}}
+
+  do_execsql_test pager1-8.$tn.3 {
+    BEGIN;
+      INSERT INTO x1 VALUES('William');
+      INSERT INTO x1 VALUES('Anne');
+    ROLLBACK;
+  } {}
+}
+
+#-------------------------------------------------------------------------
+# The next block of tests - pager1-9.* - deal with interactions between
+# the pager and the backup API. Test cases:
+#
+#   pager1-9.1.*: Test that a backup completes successfully even if the
+#                 source db is written to during the backup op.
+#
+#   pager1-9.2.*: Test that a backup completes successfully even if the
+#                 source db is written to and then rolled back during a 
+#                 backup operation.
+#
+do_test pager1-9.0.1 {
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql {
+    PRAGMA cache_size = 10;
+    BEGIN;
+      CREATE TABLE ab(a, b, UNIQUE(a, b));
+      INSERT INTO ab VALUES( a_string(200), a_string(300) );
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+      INSERT INTO ab SELECT a_string(200), a_string(300) FROM ab;
+    COMMIT;
+  }
+} {}
+do_test pager1-9.0.2 {
+  sqlite3 db2 test.db2
+  db2 eval { PRAGMA cache_size = 10 }
+  sqlite3_backup B db2 main db main
+  list [B step 10000] [B finish]
+} {SQLITE_DONE SQLITE_OK}
+do_test pager1-9.0.3 {
+ db one {SELECT md5sum(a, b) FROM ab}
+} [db2 one {SELECT md5sum(a, b) FROM ab}]
+
+do_test pager1-9.1.1 {
+  execsql { UPDATE ab SET a = a_string(201) }
+  sqlite3_backup B db2 main db main
+  B step 30
+} {SQLITE_OK}
+do_test pager1-9.1.2 {
+  execsql { UPDATE ab SET b = a_string(301) }
+  list [B step 10000] [B finish]
+} {SQLITE_DONE SQLITE_OK}
+do_test pager1-9.1.3 {
+ db one {SELECT md5sum(a, b) FROM ab}
+} [db2 one {SELECT md5sum(a, b) FROM ab}]
+do_test pager1-9.1.4 { execsql { SELECT count(*) FROM ab } } {128}
+
+do_test pager1-9.2.1 {
+  execsql { UPDATE ab SET a = a_string(202) }
+  sqlite3_backup B db2 main db main
+  B step 30
+} {SQLITE_OK}
+do_test pager1-9.2.2 {
+  execsql { 
+    BEGIN;
+      UPDATE ab SET b = a_string(301);
+    ROLLBACK;
+  }
+  list [B step 10000] [B finish]
+} {SQLITE_DONE SQLITE_OK}
+do_test pager1-9.2.3 {
+ db one {SELECT md5sum(a, b) FROM ab}
+} [db2 one {SELECT md5sum(a, b) FROM ab}]
+do_test pager1-9.2.4 { execsql { SELECT count(*) FROM ab } } {128}
+db close
+db2 close
+
+do_test pager1-9.3.1 {
+  testvfs tv -default 1
+  tv sectorsize 4096
+  faultsim_delete_and_reopen
+
+  execsql { PRAGMA page_size = 1024 }
+  for {set ii 0} {$ii < 4} {incr ii} { execsql "CREATE TABLE t${ii}(a, b)" }
+} {}
+do_test pager1-9.3.2 {
+  sqlite3 db2 test.db2
+
+  execsql {
+    PRAGMA page_size = 4096;
+    PRAGMA synchronous = OFF;
+    CREATE TABLE t1(a, b);
+    CREATE TABLE t2(a, b);
+  } db2
+
+  sqlite3_backup B db2 main db main
+  B step 30
+  list [B step 10000] [B finish]
+} {SQLITE_DONE SQLITE_OK}
+do_test pager1-9.3.3 {
+  db2 close
+  db close
+  tv delete
+  file size test.db2
+} [file size test.db]
+
+do_test pager1-9.4.1 {
+  faultsim_delete_and_reopen
+  sqlite3 db2 test.db2
+  execsql {
+    PRAGMA page_size = 4096;
+    CREATE TABLE t1(a, b);
+    CREATE TABLE t2(a, b);
+  } db2
+  sqlite3_backup B db2 main db main
+  list [B step 10000] [B finish]
+} {SQLITE_DONE SQLITE_OK}
+do_test pager1-9.4.2 {
+  list [file size test.db2] [file size test.db]
+} {0 0}
+db2 close
+
+#-------------------------------------------------------------------------
+# Test that regardless of the value returned by xSectorSize(), the
+# minimum effective sector-size is 512 and the maximum 65536 bytes.
+#
+testvfs tv -default 1
+foreach sectorsize {
+    32   64   128   256   512   1024   2048 
+    4096 8192 16384 32768 65536 131072 262144
+} {
+  tv sectorsize $sectorsize
+  set eff $sectorsize
+  if {$sectorsize < 512}   { set eff 512 }
+  if {$sectorsize > 65536} { set eff 65536 }
+
+  do_test pager1-10.$sectorsize.1 {
+    faultsim_delete_and_reopen
+    db func a_string a_string
+    execsql {
+      PRAGMA journal_mode = PERSIST;
+      PRAGMA page_size = 1024;
+      BEGIN;
+        CREATE TABLE t1(a, b);
+        CREATE TABLE t2(a, b);
+        CREATE TABLE t3(a, b);
+      COMMIT;
+    }
+    file size test.db-journal
+  } [expr $sectorsize > 65536 ? 65536 : $sectorsize]
+
+  do_test pager1-10.$sectorsize.2 {
+    execsql { 
+      INSERT INTO t3 VALUES(a_string(300), a_string(300));
+      INSERT INTO t3 SELECT * FROM t3;        /*  2 */
+      INSERT INTO t3 SELECT * FROM t3;        /*  4 */
+      INSERT INTO t3 SELECT * FROM t3;        /*  8 */
+      INSERT INTO t3 SELECT * FROM t3;        /* 16 */
+      INSERT INTO t3 SELECT * FROM t3;        /* 32 */
+    }
+  } {}
+
+  do_test pager1-10.$sectorsize.3 {
+    db close
+    sqlite3 db test.db
+    execsql { 
+      PRAGMA cache_size = 10;
+      BEGIN;
+    }
+    recursive_select 32 t3 {db eval "INSERT INTO t2 VALUES(1, 2)"}
+    execsql {
+      COMMIT;
+      SELECT * FROM t2;
+    }
+  } {1 2}
+
+  do_test pager1-10.$sectorsize.4 {
+    execsql {
+      CREATE TABLE t6(a, b);
+      CREATE TABLE t7(a, b);
+      CREATE TABLE t5(a, b);
+      DROP TABLE t6;
+      DROP TABLE t7;
+    }
+    execsql {
+      BEGIN;
+        CREATE TABLE t6(a, b);
+    }
+    recursive_select 32 t3 {db eval "INSERT INTO t5 VALUES(1, 2)"}
+    execsql {
+      COMMIT;
+      SELECT * FROM t5;
+    }
+  } {1 2}
+  
+}
+db close
+
+tv sectorsize 4096
+do_test pager1.10.x.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA auto_vacuum = none;
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(x);
+  }
+  for {set i 0} {$i<30} {incr i} {
+    execsql { INSERT INTO t1 VALUES(zeroblob(900)) }
+  }
+  file size test.db
+} {32768}
+do_test pager1.10.x.2 {
+  execsql {
+    CREATE TABLE t2(x);
+    DROP TABLE t2;
+  }
+  file size test.db
+} {33792}
+do_test pager1.10.x.3 {
+  execsql {
+    BEGIN;
+    CREATE TABLE t2(x);
+  }
+  recursive_select 30 t1
+  execsql {
+    CREATE TABLE t3(x);
+    COMMIT;
+  }
+} {}
+
+db close
+tv delete
+
+testvfs tv -default 1
+faultsim_delete_and_reopen
+db func a_string a_string
+do_execsql_test pager1-11.1 {
+  PRAGMA journal_mode = DELETE;
+  PRAGMA cache_size = 10;
+  BEGIN;
+    CREATE TABLE zz(top PRIMARY KEY);
+    INSERT INTO zz VALUES(a_string(222));
+    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
+    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
+    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
+    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
+    INSERT INTO zz SELECT a_string((SELECT 222+max(rowid) FROM zz)) FROM zz;
+  COMMIT;
+  BEGIN;
+    UPDATE zz SET top = a_string(345);
+} {delete}
+
+proc lockout {method args} { return SQLITE_IOERR }
+tv script lockout
+tv filter {xWrite xTruncate xSync}
+do_catchsql_test pager1-11.2 { COMMIT } {1 {disk I/O error}}
+
+tv script {}
+do_test pager1-11.3 {
+  sqlite3 db2 test.db
+  execsql {
+    PRAGMA journal_mode = TRUNCATE;
+    PRAGMA integrity_check;
+  } db2
+} {truncate ok}
+do_test pager1-11.4 {
+  db2 close
+  file exists test.db-journal
+} {0}
+do_execsql_test pager1-11.5 { SELECT count(*) FROM zz } {32}
+db close
+tv delete
+  
+#-------------------------------------------------------------------------
+# Test "PRAGMA page_size"
+#
+testvfs tv -default 1
+tv sectorsize 1024
+foreach pagesize {
+    512   1024   2048 4096 8192 16384 32768 
+} {
+  faultsim_delete_and_reopen
+
+  # The sector-size (according to the VFS) is 1024 bytes. So if the
+  # page-size requested using "PRAGMA page_size" is greater than the
+  # compile time value of SQLITE_MAX_PAGE_SIZE, then the effective 
+  # page-size remains 1024 bytes.
+  #
+  set eff $pagesize
+  if {$eff > $::SQLITE_MAX_PAGE_SIZE} { set eff 1024 }
+
+  do_test pager1-12.$pagesize.1 {
+    sqlite3 db2 test.db
+    execsql "
+      PRAGMA page_size = $pagesize;
+      CREATE VIEW v AS SELECT * FROM sqlite_master;
+    " db2
+    file size test.db
+  } $eff
+  do_test pager1-12.$pagesize.2 {
+    sqlite3 db2 test.db
+    execsql { 
+      SELECT count(*) FROM v;
+      PRAGMA main.page_size;
+    } db2
+  } [list 1 $eff]
+  do_test pager1-12.$pagesize.3 {
+    execsql { 
+      SELECT count(*) FROM v;
+      PRAGMA main.page_size;
+    }
+  } [list 1 $eff]
+  db2 close
+}
+db close
+tv delete
+
+#-------------------------------------------------------------------------
+# Test specal "PRAGMA journal_mode=PERSIST" test cases.
+#
+# pager1-13.1.*: This tests a special case encountered in persistent 
+#                journal mode: If the journal associated with a transaction
+#                is smaller than the journal file (because a previous 
+#                transaction left a very large non-hot journal file in the
+#                file-system), then SQLite has to be careful that there is
+#                not a journal-header left over from a previous transaction
+#                immediately following the journal content just written.
+#                If there is, and the process crashes so that the journal
+#                becomes a hot-journal and must be rolled back by another
+#                process, there is a danger that the other process may roll
+#                back the aborted transaction, then continue copying data
+#                from an older transaction from the remainder of the journal.
+#                See the syncJournal() function for details.
+#
+# pager1-13.2.*: Same test as the previous. This time, throw an index into
+#                the mix to make the integrity-check more likely to catch
+#                errors.
+#
+testvfs tv -default 1
+tv script xSyncCb
+tv filter xSync
+proc xSyncCb {method filename args} {
+  set t [file tail $filename]
+  if {$t == "test.db"} faultsim_save
+  return SQLITE_OK
+}
+faultsim_delete_and_reopen
+db func a_string a_string
+
+# The UPDATE statement at the end of this test case creates a really big
+# journal. Since the cache-size is only 10 pages, the journal contains 
+# frequent journal headers.
+#
+do_execsql_test pager1-13.1.1 {
+  PRAGMA page_size = 1024;
+  PRAGMA journal_mode = PERSIST;
+  PRAGMA cache_size = 10;
+  BEGIN;
+    CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB);
+    INSERT INTO t1 VALUES(NULL, a_string(400));
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   2 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   4 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*   8 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  16 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  32 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /*  64 */
+    INSERT INTO t1 SELECT NULL, a_string(400) FROM t1;          /* 128 */
+  COMMIT;
+  UPDATE t1 SET b = a_string(400);
+} {persist}
+
+if {$::tcl_platform(platform)!="windows"} {
+# Run transactions of increasing sizes. Eventually, one (or more than one)
+# of these will write just enough content that one of the old headers created 
+# by the transaction in the block above lies immediately after the content
+# journalled by the current transaction.
+#
+for {set nUp 1} {$nUp<64} {incr nUp} {
+  do_execsql_test pager1-13.1.2.$nUp.1 { 
+    UPDATE t1 SET b = a_string(399) WHERE a <= $nUp
+  } {}
+  do_execsql_test pager1-13.1.2.$nUp.2 { PRAGMA integrity_check } {ok} 
+
+  # Try to access the snapshot of the file-system.
+  #
+  sqlite3 db2 sv_test.db
+  do_test pager1-13.1.2.$nUp.3 {
+    execsql { SELECT sum(length(b)) FROM t1 } db2
+  } [expr {128*400 - ($nUp-1)}]
+  do_test pager1-13.1.2.$nUp.4 {
+    execsql { PRAGMA integrity_check } db2
+  } {ok}
+  db2 close
+}
+}
+
+if {$::tcl_platform(platform)!="windows"} {
+# Same test as above. But this time with an index on the table.
+#
+do_execsql_test pager1-13.2.1 {
+  CREATE INDEX i1 ON t1(b);
+  UPDATE t1 SET b = a_string(400);
+} {}
+for {set nUp 1} {$nUp<64} {incr nUp} {
+  do_execsql_test pager1-13.2.2.$nUp.1 { 
+    UPDATE t1 SET b = a_string(399) WHERE a <= $nUp
+  } {}
+  do_execsql_test pager1-13.2.2.$nUp.2 { PRAGMA integrity_check } {ok} 
+  sqlite3 db2 sv_test.db
+  do_test pager1-13.2.2.$nUp.3 {
+    execsql { SELECT sum(length(b)) FROM t1 } db2
+  } [expr {128*400 - ($nUp-1)}]
+  do_test pager1-13.2.2.$nUp.4 {
+    execsql { PRAGMA integrity_check } db2
+  } {ok}
+  db2 close
+}
+}
+
+db close
+tv delete
+
+#-------------------------------------------------------------------------
+# Test specal "PRAGMA journal_mode=OFF" test cases.
+#
+faultsim_delete_and_reopen
+do_execsql_test pager1-14.1.1 {
+  PRAGMA journal_mode = OFF;
+  CREATE TABLE t1(a, b);
+  BEGIN;
+    INSERT INTO t1 VALUES(1, 2);
+  COMMIT;
+  SELECT * FROM t1;
+} {off 1 2}
+do_catchsql_test pager1-14.1.2 {
+  BEGIN;
+    INSERT INTO t1 VALUES(3, 4);
+  ROLLBACK;
+} {0 {}}
+do_execsql_test pager1-14.1.3 {
+  SELECT * FROM t1;
+} {1 2}
+do_catchsql_test pager1-14.1.4 {
+  BEGIN;
+    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
+    INSERT INTO t1(rowid, a, b) SELECT a+3, b, b FROM t1;
+} {1 {PRIMARY KEY must be unique}}
+do_execsql_test pager1-14.1.5 {
+  COMMIT;
+  SELECT * FROM t1;
+} {1 2 2 2}
+
+#-------------------------------------------------------------------------
+# Test opening and closing the pager sub-system with different values
+# for the sqlite3_vfs.szOsFile variable.
+#
+faultsim_delete_and_reopen
+do_execsql_test pager1-15.0 {
+  CREATE TABLE tx(y, z);
+  INSERT INTO tx VALUES('Ayutthaya', 'Beijing');
+  INSERT INTO tx VALUES('London', 'Tokyo');
+} {}
+db close
+for {set i 0} {$i<513} {incr i 3} {
+  testvfs tv -default 1 -szosfile $i
+  sqlite3 db test.db
+  do_execsql_test pager1-15.$i.1 {
+    SELECT * FROM tx;
+  } {Ayutthaya Beijing London Tokyo}
+  db close
+  tv delete
+}
+
+#-------------------------------------------------------------------------
+# Check that it is not possible to open a database file if the full path
+# to the associated journal file will be longer than sqlite3_vfs.mxPathname.
+#
+testvfs tv -default 1
+tv script xOpenCb
+tv filter xOpen
+proc xOpenCb {method filename args} {
+  set ::file_len [string length $filename]
+}
+sqlite3 db test.db
+db close
+tv delete
+
+for {set ii [expr $::file_len-5]} {$ii < [expr $::file_len+20]} {incr ii} {
+  testvfs tv -default 1 -mxpathname $ii
+
+  # The length of the full path to file "test.db-journal" is ($::file_len+8).
+  # If the configured sqlite3_vfs.mxPathname value greater than or equal to
+  # this, then the file can be opened. Otherwise, it cannot.
+  #
+  if {$ii >= [expr $::file_len+8]} {
+    set res {0 {}}
+  } else {
+    set res {1 {unable to open database file}}
+  }
+
+  do_test pager1-16.1.$ii {
+    list [catch { sqlite3 db test.db } msg] $msg
+  } $res
+
+  catch {db close}
+  tv delete
+}
+
+#-------------------------------------------------------------------------
+# Test "PRAGMA omit_readlock". 
+#
+#   pager1-17.$tn.1.*: Test that if a second connection has an open 
+#                      read-transaction, it is not usually possible to write 
+#                      the database.
+#
+#   pager1-17.$tn.2.*: Test that if the second connection was opened with
+#                      the SQLITE_OPEN_READONLY flag, and 
+#                      "PRAGMA omit_readlock = 1" is executed before attaching
+#                      the database and opening a read-transaction on it, it is
+#                      possible to write the db.
+#
+#   pager1-17.$tn.3.*: Test that if the second connection was *not* opened with
+#                      the SQLITE_OPEN_READONLY flag, executing 
+#                      "PRAGMA omit_readlock = 1" has no effect.
+#
+do_multiclient_test tn {
+  do_test pager1-17.$tn.1.1 {
+    sql1 { 
+      CREATE TABLE t1(a, b);
+      INSERT INTO t1 VALUES(1, 2);
+    }
+    sql2 {
+      BEGIN;
+      SELECT * FROM t1;
+    }
+  } {1 2}
+  do_test pager1-17.$tn.1.2 {
+    csql1 { INSERT INTO t1 VALUES(3, 4) }
+  } {1 {database is locked}}
+  do_test pager1-17.$tn.1.3 {
+    sql2 { COMMIT }
+    sql1 { INSERT INTO t1 VALUES(3, 4) }
+  } {}
+
+  do_test pager1-17.$tn.2.1 {
+    code2 {
+      db2 close
+      sqlite3 db2 :memory: -readonly 1
+    }
+    sql2 { 
+      PRAGMA omit_readlock = 1;
+      ATTACH 'test.db' AS two;
+      BEGIN;
+      SELECT * FROM t1;
+    }
+  } {1 2 3 4}
+  do_test pager1-17.$tn.2.2 { sql1 "INSERT INTO t1 VALUES(5, 6)" } {}
+  do_test pager1-17.$tn.2.3 { sql2 "SELECT * FROM t1" }            {1 2 3 4}
+  do_test pager1-17.$tn.2.4 { sql2 "COMMIT ; SELECT * FROM t1" }   {1 2 3 4 5 6}
+
+  do_test pager1-17.$tn.3.1 {
+    code2 {
+      db2 close
+      sqlite3 db2 :memory:
+    }
+    sql2 { 
+      PRAGMA omit_readlock = 1;
+      ATTACH 'test.db' AS two;
+      BEGIN;
+      SELECT * FROM t1;
+    }
+  } {1 2 3 4 5 6}
+  do_test pager1-17.$tn.3.2 {
+  csql1 { INSERT INTO t1 VALUES(3, 4) }
+  } {1 {database is locked}}
+  do_test pager1-17.$tn.3.3 { sql2 COMMIT } {}
+}
+
+#-------------------------------------------------------------------------
+# Test the pagers response to the b-tree layer requesting illegal page 
+# numbers:
+#
+#   + The locking page,
+#   + Page 0,
+#   + A page with a page number greater than (2^31-1).
+#
+# These tests will not work if SQLITE_DIRECT_OVERFLOW_READ is defined. In
+# that case IO errors are sometimes reported instead of SQLITE_CORRUPT.
+#
+ifcapable !direct_read {
+do_test pager1-18.1 {
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql { 
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(a, b);
+    INSERT INTO t1 VALUES(a_string(500), a_string(200));
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+    INSERT INTO t1 SELECT a_string(500), a_string(200) FROM t1;
+  }
+} {}
+do_test pager1-18.2 {
+  set root [db one "SELECT rootpage FROM sqlite_master"]
+  set lockingpage [expr (0x10000/1024) + 1]
+  execsql {
+    PRAGMA writable_schema = 1;
+    UPDATE sqlite_master SET rootpage = $lockingpage;
+  }
+  sqlite3 db2 test.db
+  catchsql { SELECT count(*) FROM t1 } db2
+} {1 {database disk image is malformed}}
+db2 close
+do_test pager1-18.3 {
+  execsql {
+    CREATE TABLE t2(x);
+    INSERT INTO t2 VALUES(a_string(5000));
+  }
+  set pgno [expr ([file size test.db] / 1024)-2]
+  hexio_write test.db [expr ($pgno-1)*1024] 00000000
+  sqlite3 db2 test.db
+  catchsql { SELECT length(x) FROM t2 } db2
+} {1 {database disk image is malformed}}
+db2 close
+do_test pager1-18.4 {
+  hexio_write test.db [expr ($pgno-1)*1024] 90000000
+  sqlite3 db2 test.db
+  catchsql { SELECT length(x) FROM t2 } db2
+} {1 {database disk image is malformed}}
+db2 close
+do_test pager1-18.5 {
+  sqlite3 db ""
+  execsql {
+    CREATE TABLE t1(a, b);
+    CREATE TABLE t2(a, b);
+    PRAGMA writable_schema = 1;
+    UPDATE sqlite_master SET rootpage=5 WHERE tbl_name = 't1';
+    PRAGMA writable_schema = 0;
+    ALTER TABLE t1 RENAME TO x1;
+  }
+  catchsql { SELECT * FROM x1 }
+} {1 {database disk image is malformed}}
+db close
+
+do_test pager1-18.6 {
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql {
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(x);
+    INSERT INTO t1 VALUES(a_string(800));
+    INSERT INTO t1 VALUES(a_string(800));
+  }
+
+  set root [db one "SELECT rootpage FROM sqlite_master"]
+  db close
+
+  hexio_write test.db [expr ($root-1)*1024 + 8] 00000000
+  sqlite3 db test.db
+  catchsql { SELECT length(x) FROM t1 }
+} {1 {database disk image is malformed}}
+}
+
+do_test pager1-19.1 {
+  sqlite3 db ""
+  db func a_string a_string
+  execsql {
+    PRAGMA page_size = 512;
+    PRAGMA auto_vacuum = 1;
+    CREATE TABLE t1(aa, ab, ac, ad, ae, af, ag, ah, ai, aj, ak, al, am, an,
+                    ba, bb, bc, bd, be, bf, bg, bh, bi, bj, bk, bl, bm, bn,
+                    ca, cb, cc, cd, ce, cf, cg, ch, ci, cj, ck, cl, cm, cn,
+                    da, db, dc, dd, de, df, dg, dh, di, dj, dk, dl, dm, dn,
+                    ea, eb, ec, ed, ee, ef, eg, eh, ei, ej, ek, el, em, en,
+                    fa, fb, fc, fd, fe, ff, fg, fh, fi, fj, fk, fl, fm, fn,
+                    ga, gb, gc, gd, ge, gf, gg, gh, gi, gj, gk, gl, gm, gn,
+                    ha, hb, hc, hd, he, hf, hg, hh, hi, hj, hk, hl, hm, hn,
+                    ia, ib, ic, id, ie, if, ig, ih, ii, ij, ik, il, im, ix,
+                    ja, jb, jc, jd, je, jf, jg, jh, ji, jj, jk, jl, jm, jn,
+                    ka, kb, kc, kd, ke, kf, kg, kh, ki, kj, kk, kl, km, kn,
+                    la, lb, lc, ld, le, lf, lg, lh, li, lj, lk, ll, lm, ln,
+                    ma, mb, mc, md, me, mf, mg, mh, mi, mj, mk, ml, mm, mn
+    );
+    CREATE TABLE t2(aa, ab, ac, ad, ae, af, ag, ah, ai, aj, ak, al, am, an,
+                    ba, bb, bc, bd, be, bf, bg, bh, bi, bj, bk, bl, bm, bn,
+                    ca, cb, cc, cd, ce, cf, cg, ch, ci, cj, ck, cl, cm, cn,
+                    da, db, dc, dd, de, df, dg, dh, di, dj, dk, dl, dm, dn,
+                    ea, eb, ec, ed, ee, ef, eg, eh, ei, ej, ek, el, em, en,
+                    fa, fb, fc, fd, fe, ff, fg, fh, fi, fj, fk, fl, fm, fn,
+                    ga, gb, gc, gd, ge, gf, gg, gh, gi, gj, gk, gl, gm, gn,
+                    ha, hb, hc, hd, he, hf, hg, hh, hi, hj, hk, hl, hm, hn,
+                    ia, ib, ic, id, ie, if, ig, ih, ii, ij, ik, il, im, ix,
+                    ja, jb, jc, jd, je, jf, jg, jh, ji, jj, jk, jl, jm, jn,
+                    ka, kb, kc, kd, ke, kf, kg, kh, ki, kj, kk, kl, km, kn,
+                    la, lb, lc, ld, le, lf, lg, lh, li, lj, lk, ll, lm, ln,
+                    ma, mb, mc, md, me, mf, mg, mh, mi, mj, mk, ml, mm, mn
+    );
+    INSERT INTO t1(aa) VALUES( a_string(100000) );
+    INSERT INTO t2(aa) VALUES( a_string(100000) );
+    VACUUM;
+  }
+} {}
+
+#-------------------------------------------------------------------------
+# Test a couple of special cases that come up while committing 
+# transactions:
+#
+#   pager1-20.1.*: Committing an in-memory database transaction when the 
+#                  database has not been modified at all.
+#
+#   pager1-20.2.*: As above, but with a normal db in exclusive-locking mode.
+#
+#   pager1-20.3.*: Committing a transaction in WAL mode where the database has
+#                  been modified, but all dirty pages have been flushed to 
+#                  disk before the commit.
+#
+do_test pager1-20.1.1 {
+  catch {db close}
+  sqlite3 db :memory:
+  execsql {
+    CREATE TABLE one(two, three);
+    INSERT INTO one VALUES('a', 'b');
+  }
+} {}
+do_test pager1-20.1.2 {
+  execsql {
+    BEGIN EXCLUSIVE;
+    COMMIT;
+  }
+} {}
+
+do_test pager1-20.2.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA locking_mode = exclusive;
+    PRAGMA journal_mode = persist;
+    CREATE TABLE one(two, three);
+    INSERT INTO one VALUES('a', 'b');
+  }
+} {exclusive persist}
+do_test pager1-20.2.2 {
+  execsql {
+    BEGIN EXCLUSIVE;
+    COMMIT;
+  }
+} {}
+
+ifcapable wal {
+  do_test pager1-20.3.1 {
+    faultsim_delete_and_reopen
+    db func a_string a_string
+    execsql {
+      PRAGMA cache_size = 10;
+      PRAGMA journal_mode = wal;
+      BEGIN;
+        CREATE TABLE t1(x);
+        CREATE TABLE t2(y);
+        INSERT INTO t1 VALUES(a_string(800));
+        INSERT INTO t1 SELECT a_string(800) FROM t1;         /*   2 */
+        INSERT INTO t1 SELECT a_string(800) FROM t1;         /*   4 */
+        INSERT INTO t1 SELECT a_string(800) FROM t1;         /*   8 */
+        INSERT INTO t1 SELECT a_string(800) FROM t1;         /*  16 */
+        INSERT INTO t1 SELECT a_string(800) FROM t1;         /*  32 */
+      COMMIT;
+    }
+  } {wal}
+  do_test pager1-20.3.2 {
+    execsql {
+      BEGIN;
+      INSERT INTO t2 VALUES('xxxx');
+    }
+    recursive_select 32 t1
+    execsql COMMIT
+  } {}
+}
+
+#-------------------------------------------------------------------------
+# Test that a WAL database may not be opened if:
+#
+#   pager1-21.1.*: The VFS has an iVersion less than 2, or
+#   pager1-21.2.*: The VFS does not provide xShmXXX() methods.
+#
+ifcapable wal {
+  do_test pager1-21.0 {
+    faultsim_delete_and_reopen
+    execsql {
+      PRAGMA journal_mode = WAL;
+      CREATE TABLE ko(c DEFAULT 'abc', b DEFAULT 'def');
+      INSERT INTO ko DEFAULT VALUES;
+    }
+  } {wal}
+  do_test pager1-21.1 {
+    testvfs tv -noshm 1
+    sqlite3 db2 test.db -vfs tv
+    catchsql { SELECT * FROM ko } db2
+  } {1 {unable to open database file}}
+  db2 close
+  tv delete
+  do_test pager1-21.2 {
+    testvfs tv -iversion 1
+    sqlite3 db2 test.db -vfs tv
+    catchsql { SELECT * FROM ko } db2
+  } {1 {unable to open database file}}
+  db2 close
+  tv delete
+}
+
+#-------------------------------------------------------------------------
+# Test that a "PRAGMA wal_checkpoint":
+#
+#   pager1-22.1.*: is a no-op on a non-WAL db, and
+#   pager1-22.2.*: does not cause xSync calls with a synchronous=off db.
+#
+ifcapable wal {
+  do_test pager1-22.1.1 {
+    faultsim_delete_and_reopen
+    execsql {
+      CREATE TABLE ko(c DEFAULT 'abc', b DEFAULT 'def');
+      INSERT INTO ko DEFAULT VALUES;
+    }
+    execsql { PRAGMA wal_checkpoint }
+  } {0 -1 -1}
+  do_test pager1-22.2.1 {
+    testvfs tv -default 1
+    tv filter xSync
+    tv script xSyncCb
+    proc xSyncCb {args} {incr ::synccount}
+    set ::synccount 0
+    sqlite3 db test.db
+    execsql {
+      PRAGMA synchronous = off;
+      PRAGMA journal_mode = WAL;
+      INSERT INTO ko DEFAULT VALUES;
+    }
+    execsql { PRAGMA wal_checkpoint }
+    set synccount
+  } {0}
+  db close
+  tv delete
+}
+
+#-------------------------------------------------------------------------
+# Tests for changing journal mode.
+#
+#   pager1-23.1.*: Test that when changing from PERSIST to DELETE mode,
+#                  the journal file is deleted.
+#
+#   pager1-23.2.*: Same test as above, but while a shared lock is held
+#                  on the database file.
+#
+#   pager1-23.3.*: Same test as above, but while a reserved lock is held
+#                  on the database file.
+#
+#   pager1-23.4.*: And, for fun, while holding an exclusive lock.
+#
+#   pager1-23.5.*: Try to set various different journal modes with an
+#                  in-memory database (only MEMORY and OFF should work).
+#
+#   pager1-23.6.*: Try to set locking_mode=normal on an in-memory database
+#                  (doesn't work - in-memory databases always use
+#                  locking_mode=exclusive).
+#
+do_test pager1-23.1.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA journal_mode = PERSIST;
+    CREATE TABLE t1(a, b);
+  }
+  file exists test.db-journal
+} {1}
+do_test pager1-23.1.2 {
+  execsql { PRAGMA journal_mode = DELETE }
+  file exists test.db-journal
+} {0}
+
+do_test pager1-23.2.1 {
+  execsql {
+    PRAGMA journal_mode = PERSIST;
+    INSERT INTO t1 VALUES('Canberra', 'ACT');
+  }
+  db eval { SELECT * FROM t1 } {
+    db eval { PRAGMA journal_mode = DELETE }
+  }
+  execsql { PRAGMA journal_mode }
+} {delete}
+do_test pager1-23.2.2 {
+  file exists test.db-journal
+} {0}
+
+do_test pager1-23.3.1 {
+  execsql {
+    PRAGMA journal_mode = PERSIST;
+    INSERT INTO t1 VALUES('Darwin', 'NT');
+    BEGIN IMMEDIATE;
+  }
+  db eval { PRAGMA journal_mode = DELETE }
+  execsql { PRAGMA journal_mode }
+} {delete}
+do_test pager1-23.3.2 {
+  file exists test.db-journal
+} {0}
+do_test pager1-23.3.3 {
+  execsql COMMIT
+} {}
+
+do_test pager1-23.4.1 {
+  execsql {
+    PRAGMA journal_mode = PERSIST;
+    INSERT INTO t1 VALUES('Adelaide', 'SA');
+    BEGIN EXCLUSIVE;
+  }
+  db eval { PRAGMA journal_mode = DELETE }
+  execsql { PRAGMA journal_mode }
+} {delete}
+do_test pager1-23.4.2 {
+  file exists test.db-journal
+} {0}
+do_test pager1-23.4.3 {
+  execsql COMMIT
+} {}
+
+do_test pager1-23.5.1 {
+  faultsim_delete_and_reopen
+  sqlite3 db :memory:
+} {}
+foreach {tn mode possible} {
+  2  off      1
+  3  memory   1
+  4  persist  0
+  5  delete   0
+  6  wal      0
+  7  truncate 0
+} {
+  do_test pager1-23.5.$tn.1 {
+    execsql "PRAGMA journal_mode = off"
+    execsql "PRAGMA journal_mode = $mode"
+  } [if $possible {list $mode} {list off}]
+  do_test pager1-23.5.$tn.2 {
+    execsql "PRAGMA journal_mode = memory"
+    execsql "PRAGMA journal_mode = $mode"
+  } [if $possible {list $mode} {list memory}]
+}
+do_test pager1-23.6.1 {
+  execsql {PRAGMA locking_mode = normal}
+} {exclusive}
+do_test pager1-23.6.2 {
+  execsql {PRAGMA locking_mode = exclusive}
+} {exclusive}
+do_test pager1-23.6.3 {
+  execsql {PRAGMA locking_mode}
+} {exclusive}
+do_test pager1-23.6.4 {
+  execsql {PRAGMA main.locking_mode}
+} {exclusive}
+
+#-------------------------------------------------------------------------
+#
+do_test pager1-24.1.1 {
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql {
+    PRAGMA cache_size = 10;
+    PRAGMA auto_vacuum = FULL;
+    CREATE TABLE x1(x, y, z, PRIMARY KEY(y, z));
+    CREATE TABLE x2(x, y, z, PRIMARY KEY(y, z));
+    INSERT INTO x2 VALUES(a_string(400), a_string(500), a_string(600));
+    INSERT INTO x2 SELECT a_string(600), a_string(400), a_string(500) FROM x2;
+    INSERT INTO x2 SELECT a_string(500), a_string(600), a_string(400) FROM x2;
+    INSERT INTO x2 SELECT a_string(400), a_string(500), a_string(600) FROM x2;
+    INSERT INTO x2 SELECT a_string(600), a_string(400), a_string(500) FROM x2;
+    INSERT INTO x2 SELECT a_string(500), a_string(600), a_string(400) FROM x2;
+    INSERT INTO x2 SELECT a_string(400), a_string(500), a_string(600) FROM x2;
+    INSERT INTO x1 SELECT * FROM x2;
+  }
+} {}
+do_test pager1-24.1.2 {
+  execsql {
+    BEGIN;
+      DELETE FROM x1 WHERE rowid<32;
+  }
+  recursive_select 64 x2
+} {}
+do_test pager1-24.1.3 {
+  execsql { 
+      UPDATE x1 SET z = a_string(300) WHERE rowid>40;
+    COMMIT;
+    PRAGMA integrity_check;
+    SELECT count(*) FROM x1;
+  }
+} {ok 33}
+
+do_test pager1-24.1.4 {
+  execsql {
+    DELETE FROM x1;
+    INSERT INTO x1 SELECT * FROM x2;
+    BEGIN;
+      DELETE FROM x1 WHERE rowid<32;
+      UPDATE x1 SET z = a_string(299) WHERE rowid>40;
+  }
+  recursive_select 64 x2 {db eval COMMIT}
+  execsql {
+    PRAGMA integrity_check;
+    SELECT count(*) FROM x1;
+  }
+} {ok 33}
+
+do_test pager1-24.1.5 {
+  execsql {
+    DELETE FROM x1;
+    INSERT INTO x1 SELECT * FROM x2;
+  }
+  recursive_select 64 x2 { db eval {CREATE TABLE x3(x, y, z)} }
+  execsql { SELECT * FROM x3 }
+} {}
+
+#-------------------------------------------------------------------------
+#
+do_test pager1-25-1 {
+  faultsim_delete_and_reopen
+  execsql {
+    BEGIN;
+      SAVEPOINT abc;
+        CREATE TABLE t1(a, b);
+      ROLLBACK TO abc;
+    COMMIT;
+  }
+  db close
+} {}
+breakpoint
+do_test pager1-25-2 {
+  faultsim_delete_and_reopen
+  execsql {
+    SAVEPOINT abc;
+      CREATE TABLE t1(a, b);
+    ROLLBACK TO abc;
+    COMMIT;
+  }
+  db close
+} {}
+
+#-------------------------------------------------------------------------
+# Sector-size tests.
+#
+do_test pager1-26.1 {
+  testvfs tv -default 1
+  tv sectorsize 4096
+  faultsim_delete_and_reopen
+  db func a_string a_string
+  execsql {
+    PRAGMA page_size = 512;
+    CREATE TABLE tbl(a PRIMARY KEY, b UNIQUE);
+    BEGIN;
+      INSERT INTO tbl VALUES(a_string(25), a_string(600));
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+      INSERT INTO tbl SELECT a_string(25), a_string(600) FROM tbl;
+    COMMIT;
+  }
+} {}
+do_execsql_test pager1-26.1 {
+  UPDATE tbl SET b = a_string(550);
+} {}
+db close
+tv delete
+
+#-------------------------------------------------------------------------
+#
+do_test pager1.27.1 {
+  faultsim_delete_and_reopen
+  sqlite3_pager_refcounts db
+  execsql {
+    BEGIN;
+      CREATE TABLE t1(a, b);
+  }
+  sqlite3_pager_refcounts db
+  execsql COMMIT
+} {}
+
+#-------------------------------------------------------------------------
+# Test that attempting to open a write-transaction with 
+# locking_mode=exclusive in WAL mode fails if there are other clients on 
+# the same database.
+#
+catch { db close }
+ifcapable wal {
+  do_multiclient_test tn {
+    do_test pager1-28.$tn.1 {
+      sql1 { 
+        PRAGMA journal_mode = WAL;
+        CREATE TABLE t1(a, b);
+        INSERT INTO t1 VALUES('a', 'b');
+      }
+    } {wal}
+    do_test pager1-28.$tn.2 { sql2 { SELECT * FROM t1 } } {a b}
+
+    do_test pager1-28.$tn.3 { sql1 { PRAGMA locking_mode=exclusive } } {exclusive}
+    do_test pager1-28.$tn.4 { 
+      csql1 { BEGIN; INSERT INTO t1 VALUES('c', 'd'); }
+    } {1 {database is locked}}
+    code2 { db2 close ; sqlite3 db2 test.db }
+    do_test pager1-28.$tn.4 { 
+      sql1 { INSERT INTO t1 VALUES('c', 'd'); COMMIT }
+    } {}
+  }
+}
+
+#-------------------------------------------------------------------------
+# Normally, when changing from journal_mode=PERSIST to DELETE the pager
+# attempts to delete the journal file. However, if it cannot obtain a
+# RESERVED lock on the database file, this step is skipped.
+#
+do_multiclient_test tn {
+  do_test pager1-28.$tn.1 {
+    sql1 { 
+      PRAGMA journal_mode = PERSIST;
+      CREATE TABLE t1(a, b);
+      INSERT INTO t1 VALUES('a', 'b');
+    }
+  } {persist}
+  do_test pager1-28.$tn.2 { file exists test.db-journal } 1
+  do_test pager1-28.$tn.3 { sql1 { PRAGMA journal_mode = DELETE } } delete
+  do_test pager1-28.$tn.4 { file exists test.db-journal } 0
+
+  do_test pager1-28.$tn.5 {
+    sql1 { 
+      PRAGMA journal_mode = PERSIST;
+      INSERT INTO t1 VALUES('c', 'd');
+    }
+  } {persist}
+  do_test pager1-28.$tn.6 { file exists test.db-journal } 1
+  do_test pager1-28.$tn.7 {
+    sql2 { BEGIN; INSERT INTO t1 VALUES('e', 'f'); }
+  } {}
+  do_test pager1-28.$tn.8  { file exists test.db-journal } 1
+  do_test pager1-28.$tn.9  { sql1 { PRAGMA journal_mode = DELETE } } delete
+  do_test pager1-28.$tn.10 { file exists test.db-journal } 1
+
+  do_test pager1-28.$tn.11 { sql2 COMMIT } {}
+  do_test pager1-28.$tn.12 { file exists test.db-journal } 0
+
+  do_test pager1-28-$tn.13 {
+    code1 { set channel [db incrblob -readonly t1 a 2] }
+    sql1 {
+      PRAGMA journal_mode = PERSIST;
+      INSERT INTO t1 VALUES('g', 'h');
+    }
+  } {persist}
+  do_test pager1-28.$tn.14 { file exists test.db-journal } 1
+  do_test pager1-28.$tn.15 {
+    sql2 { BEGIN; INSERT INTO t1 VALUES('e', 'f'); }
+  } {}
+  do_test pager1-28.$tn.16 { sql1 { PRAGMA journal_mode = DELETE } } delete
+  do_test pager1-28.$tn.17 { file exists test.db-journal } 1
+
+  do_test pager1-28.$tn.17 { csql2 { COMMIT } } {1 {database is locked}}
+  do_test pager1-28-$tn.18 { code1 { read $channel } } c
+  do_test pager1-28-$tn.19 { code1 { close $channel } } {}
+  do_test pager1-28.$tn.20 { sql2 { COMMIT } } {}
+}
+
+do_test pager1-29.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA page_size = 1024;
+    PRAGMA auto_vacuum = full;
+    PRAGMA locking_mode=exclusive;
+    CREATE TABLE t1(a, b);
+    INSERT INTO t1 VALUES(1, 2);
+  }
+  file size test.db
+} [expr 1024*3]
+do_test pager1-29.2 {
+  execsql {
+    PRAGMA page_size = 4096;
+    VACUUM;
+  }
+  file size test.db
+} [expr 4096*3]
+
+#-------------------------------------------------------------------------
+# Test that if an empty database file (size 0 bytes) is opened in 
+# exclusive-locking mode, any journal file is deleted from the file-system
+# without being rolled back. And that the RESERVED lock obtained while
+# doing this is not released.
+#
+do_test pager1-30.1 {
+  db close
+  delete_file test.db
+  delete_file test.db-journal
+  set fd [open test.db-journal w]
+  seek $fd [expr 512+1032*2]
+  puts -nonewline $fd x
+  close $fd
+
+  sqlite3 db test.db
+  execsql {
+    PRAGMA locking_mode=EXCLUSIVE;
+    SELECT count(*) FROM sqlite_master;
+    PRAGMA lock_status;
+  }
+} {exclusive 0 main reserved temp closed}
+
+#-------------------------------------------------------------------------
+# Test that if the "page-size" field in a journal-header is 0, the journal
+# file can still be rolled back. This is required for backward compatibility -
+# versions of SQLite prior to 3.5.8 always set this field to zero.
+#
+if {$tcl_platform(platform)=="unix"} {
+do_test pager1-31.1 {
+  faultsim_delete_and_reopen
+  execsql {
+    PRAGMA cache_size = 10;
+    PRAGMA page_size = 1024;
+    CREATE TABLE t1(x, y, UNIQUE(x, y));
+    INSERT INTO t1 VALUES(randomblob(1500), randomblob(1500));
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    INSERT INTO t1 SELECT randomblob(1500), randomblob(1500) FROM t1;
+    BEGIN;
+      UPDATE t1 SET y = randomblob(1499);
+  }
+  copy_file test.db test.db2
+  copy_file test.db-journal test.db2-journal
+  
+  hexio_write test.db2-journal 24 00000000
+  sqlite3 db2 test.db2
+  execsql { PRAGMA integrity_check } db2
+} {ok}
+}
+
+#-------------------------------------------------------------------------
+# Test that a database file can be "pre-hinted" to a certain size and that
+# subsequent spilling of the pager cache does not result in the database
+# file being shrunk.
+#
+catch {db close}
+forcedelete test.db
+
+do_test pager1-32.1 {
+  sqlite3 db test.db
+  execsql {
+    CREATE TABLE t1(x, y);
+  }
+  db close
+  sqlite3 db test.db
+  execsql {
+    BEGIN;
+    INSERT INTO t1 VALUES(1, randomblob(10000));
+  }
+  file_control_chunksize_test db main 1024
+  file_control_sizehint_test db main 20971520; # 20MB
+  execsql {
+    PRAGMA cache_size = 10;
+    INSERT INTO t1 VALUES(1, randomblob(10000));
+    INSERT INTO t1 VALUES(2, randomblob(10000));
+    INSERT INTO t1 SELECT x+2, randomblob(10000) from t1;
+    INSERT INTO t1 SELECT x+4, randomblob(10000) from t1;
+    INSERT INTO t1 SELECT x+8, randomblob(10000) from t1;
+    INSERT INTO t1 SELECT x+16, randomblob(10000) from t1;
+    SELECT count(*) FROM t1;
+    COMMIT;
+  }
+  db close
+  file size test.db
+} {20971520}
+
+# Cleanup 20MB file left by the previous test.
+forcedelete test.db
+
+finish_test