diff --git a/manifest b/manifest
index d869216321..9a1539d2ca 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\soff-by-one\sbug\sin\s[c3939d2491]\suncovered\sby\sth3.
-D 2013-02-23T17:49:16.450
+C Enhancements\sto\stest\sscripts.\sNo\scode\schanges.
+D 2013-02-23T18:58:11.423
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in a48faa9e7dd7d556d84f5456eabe5825dd8a6282
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -229,7 +229,7 @@ F src/test_superlock.c 2b97936ca127d13962c3605dbc9a4ef269c424cd
 F src/test_syscall.c a992d8c80ea91fbf21fb2dd570db40e77dd7e6ae
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
 F src/test_thread.c e286f2173563f2a1747c24bcda6b9d030bf4f4e4
-F src/test_vfs.c c6260ef238c1142c8f8bd402db02216afd182ae3
+F src/test_vfs.c fb16b2d9938cf0c1afc5a423b55b952fcc024275
 F src/test_vfstrace.c 34b544e80ba7fb77be15395a609c669df2e660a2
 F src/test_wholenumber.c 3d2b9ed1505c40ad5c5ca2ad16ae7a289d6cc251
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
@@ -534,7 +534,7 @@ F test/incrblob_err.test d2562d2771ebffd4b3af89ef64c140dd44371597
 F test/incrblobfault.test 917c0292224c64a56ef7215fd633a3a82f805be0
 F test/incrvacuum.test d2a6ddf5e429720b5fe502766af747915ccf6c32
 F test/incrvacuum2.test 379eeb8740b0ef60c372c439ad4cbea20b34bb9b
-F test/incrvacuum_ioerr.test 22f208d01c528403240e05beecc41dc98ed01637
+F test/incrvacuum_ioerr.test 293f2714571255539c8c789da2f7de4ec3f7101e
 F test/index.test b5429732b3b983fa810e3ac867d7ca85dae35097
 F test/index2.test ee83c6b5e3173a3d7137140d945d9a5d4fdfb9d6
 F test/index3.test 423a25c789fc8cc51aaf2a4370bbdde2d9e9eed7
@@ -752,7 +752,7 @@ F test/tclsqlite.test 37a61c2da7e3bfe3b8c1a2867199f6b860df5d43
 F test/tempdb.test 19d0f66e2e3eeffd68661a11c83ba5e6ace9128c
 F test/temptable.test 51edd31c65ed1560dd600b1796e8325df96318e2
 F test/temptrigger.test 26670ed7a39cf2296a7f0a9e0a1d7bdb7abe936d
-F test/tester.tcl 0560b09498876da7714fff680c5d892b9228862f
+F test/tester.tcl 2918ebca150b67ca25b1682f8ecd857af77fab05
 F test/thread001.test 9f22fd3525a307ff42a326b6bc7b0465be1745a5
 F test/thread002.test e630504f8a06c00bf8bbe68528774dd96aeb2e58
 F test/thread003.test ee4c9efc3b86a6a2767516a37bd64251272560a7
@@ -1034,7 +1034,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P b73847f17b7ae1298dfc52de6c4c4bc809bc77a3
-R 34a70e559a11e4b7cf3c06168257f235
+P 66f9faa9a969d004486ee38d492fb3eda6cdebab
+R 87b39f8ba9e2866ed1adab1a9b990f83
 U dan
-Z 1b7c8c9ddd8f5c22095277131689ae60
+Z c23ef7906674057cc290bb43146b99c4
diff --git a/manifest.uuid b/manifest.uuid
index bda95df179..265b085615 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-66f9faa9a969d004486ee38d492fb3eda6cdebab
\ No newline at end of file
+ccab94c10d54e585de918bbf82dec188287d93b2
\ No newline at end of file
diff --git a/src/test_vfs.c b/src/test_vfs.c
index 93c556b56e..933de99515 100644
--- a/src/test_vfs.c
+++ b/src/test_vfs.c
@@ -265,7 +265,8 @@ static void tvfsExecTcl(
   const char *zMethod,
   Tcl_Obj *arg1,
   Tcl_Obj *arg2,
-  Tcl_Obj *arg3
+  Tcl_Obj *arg3,
+  Tcl_Obj *arg4
 ){
   int rc;                         /* Return code from Tcl_EvalObj() */
   Tcl_Obj *pEval;
@@ -282,6 +283,7 @@ static void tvfsExecTcl(
   if( arg1 ) Tcl_ListObjAppendElement(p->interp, pEval, arg1);
   if( arg2 ) Tcl_ListObjAppendElement(p->interp, pEval, arg2);
   if( arg3 ) Tcl_ListObjAppendElement(p->interp, pEval, arg3);
+  if( arg4 ) Tcl_ListObjAppendElement(p->interp, pEval, arg4);
 
   rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
   if( rc!=TCL_OK ){
@@ -302,7 +304,7 @@ static int tvfsClose(sqlite3_file *pFile){
 
   if( p->pScript && p->mask&TESTVFS_CLOSE_MASK ){
     tvfsExecTcl(p, "xClose", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
   }
 
@@ -333,7 +335,7 @@ static int tvfsRead(
   Testvfs *p = (Testvfs *)pFd->pVfs->pAppData;
   if( p->pScript && p->mask&TESTVFS_READ_MASK ){
     tvfsExecTcl(p, "xRead", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -362,7 +364,7 @@ static int tvfsWrite(
   if( p->pScript && p->mask&TESTVFS_WRITE_MASK ){
     tvfsExecTcl(p, "xWrite", 
         Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 
-        Tcl_NewWideIntObj(iOfst)
+        Tcl_NewWideIntObj(iOfst), Tcl_NewIntObj(iAmt)
     );
     tvfsResultCode(p, &rc);
   }
@@ -390,7 +392,7 @@ static int tvfsTruncate(sqlite3_file *pFile, sqlite_int64 size){
 
   if( p->pScript && p->mask&TESTVFS_TRUNCATE_MASK ){
     tvfsExecTcl(p, "xTruncate", 
-        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -431,7 +433,7 @@ static int tvfsSync(sqlite3_file *pFile, int flags){
 
     tvfsExecTcl(p, "xSync", 
         Tcl_NewStringObj(pFd->zFilename, -1), pFd->pShmId,
-        Tcl_NewStringObj(zFlags, -1)
+        Tcl_NewStringObj(zFlags, -1), 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -578,7 +580,7 @@ static int tvfsOpen(
         z += strlen(z) + 1;
       }
     }
-    tvfsExecTcl(p, "xOpen", Tcl_NewStringObj(pFd->zFilename, -1), pArg, 0);
+    tvfsExecTcl(p, "xOpen", Tcl_NewStringObj(pFd->zFilename, -1), pArg, 0, 0);
     Tcl_DecrRefCount(pArg);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
@@ -635,7 +637,7 @@ static int tvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
 
   if( p->pScript && p->mask&TESTVFS_DELETE_MASK ){
     tvfsExecTcl(p, "xDelete", 
-        Tcl_NewStringObj(zPath, -1), Tcl_NewIntObj(dirSync), 0
+        Tcl_NewStringObj(zPath, -1), Tcl_NewIntObj(dirSync), 0, 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -663,7 +665,7 @@ static int tvfsAccess(
     if( flags==SQLITE_ACCESS_READWRITE ) zArg = "SQLITE_ACCESS_READWRITE";
     if( flags==SQLITE_ACCESS_READ ) zArg = "SQLITE_ACCESS_READ";
     tvfsExecTcl(p, "xAccess", 
-        Tcl_NewStringObj(zPath, -1), Tcl_NewStringObj(zArg, -1), 0
+        Tcl_NewStringObj(zPath, -1), Tcl_NewStringObj(zArg, -1), 0, 0
     );
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
@@ -691,7 +693,7 @@ static int tvfsFullPathname(
   Testvfs *p = (Testvfs *)pVfs->pAppData;
   if( p->pScript && p->mask&TESTVFS_FULLPATHNAME_MASK ){
     int rc;
-    tvfsExecTcl(p, "xFullPathname", Tcl_NewStringObj(zPath, -1), 0, 0);
+    tvfsExecTcl(p, "xFullPathname", Tcl_NewStringObj(zPath, -1), 0, 0, 0);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
     }
@@ -771,7 +773,7 @@ static int tvfsShmOpen(sqlite3_file *pFile){
   */
   Tcl_ResetResult(p->interp);
   if( p->pScript && p->mask&TESTVFS_SHMOPEN_MASK ){
-    tvfsExecTcl(p, "xShmOpen", Tcl_NewStringObj(pFd->zFilename, -1), 0, 0);
+    tvfsExecTcl(p, "xShmOpen", Tcl_NewStringObj(pFd->zFilename, -1), 0, 0, 0);
     if( tvfsResultCode(p, &rc) ){
       if( rc!=SQLITE_OK ) return rc;
     }
@@ -841,7 +843,7 @@ static int tvfsShmMap(
     Tcl_ListObjAppendElement(p->interp, pArg, Tcl_NewIntObj(pgsz));
     Tcl_ListObjAppendElement(p->interp, pArg, Tcl_NewIntObj(isWrite));
     tvfsExecTcl(p, "xShmMap", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, pArg
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, pArg, 0
     );
     tvfsResultCode(p, &rc);
     Tcl_DecrRefCount(pArg);
@@ -891,7 +893,7 @@ static int tvfsShmLock(
     }
     tvfsExecTcl(p, "xShmLock", 
         Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId,
-        Tcl_NewStringObj(zLock, -1)
+        Tcl_NewStringObj(zLock, -1), 0
     );
     tvfsResultCode(p, &rc);
   }
@@ -937,7 +939,7 @@ static void tvfsShmBarrier(sqlite3_file *pFile){
 
   if( p->pScript && p->mask&TESTVFS_SHMBARRIER_MASK ){
     tvfsExecTcl(p, "xShmBarrier", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0, 0
     );
   }
 }
@@ -961,7 +963,7 @@ static int tvfsShmUnmap(
 
   if( p->pScript && p->mask&TESTVFS_SHMCLOSE_MASK ){
     tvfsExecTcl(p, "xShmUnmap", 
-        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0
+        Tcl_NewStringObj(pFd->pShm->zFile, -1), pFd->pShmId, 0, 0
     );
     tvfsResultCode(p, &rc);
   }
diff --git a/test/incrvacuum_ioerr.test b/test/incrvacuum_ioerr.test
index 946925d7dc..aecb6f8747 100644
--- a/test/incrvacuum_ioerr.test
+++ b/test/incrvacuum_ioerr.test
@@ -139,8 +139,8 @@ ifcapable shared_cache {
     # Figure out how big the database is and how many free pages it
     # has before running incremental-vacuum.
     #
-    set nPage [expr {[file size test.db]/1024}]
     set nFree [execsql {pragma freelist_count} db1]
+    set nPage [execsql {pragma page_count} db1]
   
     # Now run incremental-vacuum to vacuum 5 pages from the db file.
     # The iTest'th I/O call is set to fail.
@@ -158,7 +158,7 @@ ifcapable shared_cache {
     set ::sqlite_io_error_hardhit 0
   
     set nFree2 [execsql {pragma freelist_count} db1]
-    set nPage2 [expr {[file size test.db]/1024}]
+    set nPage2 [execsql {pragma page_count} db1]
   
     do_test incrvacuum-ioerr-4.$iTest.2 {
       set shrink [expr {$nPage-$nPage2}]
diff --git a/test/tester.tcl b/test/tester.tcl
index a7e6c99580..f360840789 100644
--- a/test/tester.tcl
+++ b/test/tester.tcl
@@ -1118,6 +1118,25 @@ proc crashsql {args} {
   lappend r $msg
 }
 
+proc run_ioerr_prep {} {
+  set ::sqlite_io_error_pending 0
+  catch {db close}
+  catch {db2 close}
+  catch {forcedelete test.db}
+  catch {forcedelete test.db-journal}
+  catch {forcedelete test2.db}
+  catch {forcedelete test2.db-journal}
+  set ::DB [sqlite3 db test.db; sqlite3_connection_pointer db]
+  sqlite3_extended_result_codes $::DB $::ioerropts(-erc)
+  if {[info exists ::ioerropts(-tclprep)]} {
+    eval $::ioerropts(-tclprep)
+  }
+  if {[info exists ::ioerropts(-sqlprep)]} {
+    execsql $::ioerropts(-sqlprep)
+  }
+  expr 0
+}
+
 # Usage: do_ioerr_test <test number> <options...>
 #
 # This proc is used to implement test cases that check that IO errors
@@ -1150,10 +1169,26 @@ proc do_ioerr_test {testname args} {
   # TEMPORARY: For 3.5.9, disable testing of extended result codes. There are
   # a couple of obscure IO errors that do not return them.
   set ::ioerropts(-erc) 0
+  
+  # Create a single TCL script from the TCL and SQL specified
+  # as the body of the test.
+  set ::ioerrorbody {}
+  if {[info exists ::ioerropts(-tclbody)]} {
+    append ::ioerrorbody "$::ioerropts(-tclbody)\n"
+  }
+  if {[info exists ::ioerropts(-sqlbody)]} {
+    append ::ioerrorbody "db eval {$::ioerropts(-sqlbody)}"
+  }
+
+  save_prng_state
+  if {$::ioerropts(-cksum)} {
+    run_ioerr_prep
+    eval $::ioerrorbody
+    set ::goodcksum [cksum]
+  }
 
   set ::go 1
   #reset_prng_state
-  save_prng_state
   for {set n $::ioerropts(-start)} {$::go} {incr n} {
     set ::TN $n
     incr ::ioerropts(-count) -1
@@ -1170,27 +1205,12 @@ proc do_ioerr_test {testname args} {
     # Delete the files test.db and test2.db, then execute the TCL and 
     # SQL (in that order) to prepare for the test case.
     do_test $testname.$n.1 {
-      set ::sqlite_io_error_pending 0
-      catch {db close}
-      catch {db2 close}
-      catch {forcedelete test.db}
-      catch {forcedelete test.db-journal}
-      catch {forcedelete test2.db}
-      catch {forcedelete test2.db-journal}
-      set ::DB [sqlite3 db test.db; sqlite3_connection_pointer db]
-      sqlite3_extended_result_codes $::DB $::ioerropts(-erc)
-      if {[info exists ::ioerropts(-tclprep)]} {
-        eval $::ioerropts(-tclprep)
-      }
-      if {[info exists ::ioerropts(-sqlprep)]} {
-        execsql $::ioerropts(-sqlprep)
-      }
-      expr 0
+      run_ioerr_prep
     } {0}
 
     # Read the 'checksum' of the database.
     if {$::ioerropts(-cksum)} {
-      set checksum [cksum]
+      set ::checksum [cksum]
     }
 
     # Set the Nth IO error to fail.
@@ -1198,20 +1218,10 @@ proc do_ioerr_test {testname args} {
       set ::sqlite_io_error_persist $::ioerropts(-persist)
       set ::sqlite_io_error_pending $n
     }] $n
-  
-    # Create a single TCL script from the TCL and SQL specified
-    # as the body of the test.
-    set ::ioerrorbody {}
-    if {[info exists ::ioerropts(-tclbody)]} {
-      append ::ioerrorbody "$::ioerropts(-tclbody)\n"
-    }
-    if {[info exists ::ioerropts(-sqlbody)]} {
-      append ::ioerrorbody "db eval {$::ioerropts(-sqlbody)}"
-    }
 
-    # Execute the TCL Script created in the above block. If
-    # there are at least N IO operations performed by SQLite as
-    # a result of the script, the Nth will fail.
+    # Execute the TCL script created for the body of this test. If
+    # at least N IO operations performed by SQLite as a result of 
+    # the script, the Nth will fail.
     do_test $testname.$n.3 {
       set ::sqlite_io_error_hit 0
       set ::sqlite_io_error_hardhit 0
@@ -1315,8 +1325,15 @@ proc do_ioerr_test {testname args} {
         catch {db close}
         catch {db2 close}
         set ::DB [sqlite3 db test.db; sqlite3_connection_pointer db]
-        cksum
-      } $checksum
+        set nowcksum [cksum]
+        set res [expr {$nowcksum==$::checksum || $nowcksum==$::goodcksum}]
+        if {$res==0} {
+          puts "now=$nowcksum"
+          puts "the=$::checksum"
+          puts "fwd=$::goodcksum"
+        }
+        set res
+      } 1
     }
 
     set ::sqlite_io_error_hardhit 0