diff --git a/manifest b/manifest
index bf84f0f2ec..e631fa3a74 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Change\sthe\swindows\sbackend\sto\sretry\sread\sand\swrite\srequests\sif\sthe\sencounter\nERROR_LOCK_VIOLATION\sand\sERROR_SHARING_VIOLATION\serrors\s-\swhich\swe\sthink\nsometimes\shappens\sdue\sto\sagressive\santi-virus\ssoftware.
-D 2011-07-11T18:17:56.144
+C Update\sthe\sTCL\scommands\sfor\ssetting\swindows\smanditory\slocks.\nAdd\stest\scases\sfor\smanditory\slock\sdelays\sunder\swindows.
+D 2011-07-11T23:45:44.051
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in c1d7a7f4fd8da6b1815032efca950e3d5125407e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -188,7 +188,7 @@ F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
 F src/tclsqlite.c c355b33803fb756dc09297ec84d19604301fa622
-F src/test1.c 8eef932f1024f1076a8adb8a6f5d9c5267c9e969
+F src/test1.c 6623e003ce840ed4a303918dbbc124f9e222974c
 F src/test2.c 80d323d11e909cf0eb1b6fbb4ac22276483bcf31
 F src/test3.c 124ff9735fb6bb7d41de180d6bac90e7b1509432
 F src/test4.c d1e5a5e904d4b444cf572391fdcb017638e36ff7
@@ -911,6 +911,7 @@ F test/where9.test 24f19ad14bb1b831564ced5273e681e495662848
 F test/whereA.test 24c234263c8fe358f079d5e57d884fb569d2da0a
 F test/whereB.test 0def95db3bdec220a731c7e4bec5930327c1d8c5
 F test/wherelimit.test 5e9fd41e79bb2b2d588ed999d641d9c965619b31
+F test/win32lock.test 7fa3287dccc836fcaa8e0d1e77aa017de5889231
 F test/zeroblob.test caaecfb4f908f7bc086ed238668049f96774d688
 F tool/build-shell.sh 12aa4391073a777fcb6dcc490b219a018ae98bac
 F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
@@ -951,7 +952,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
 F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
-P 90b1aea17400bbda5ebc8ae4eb4e12127519e42e
-R 349c7f009f94630db798c4428c847d95
+P c20aca06610407c197ea50ea77c2591aacf2252a
+R 4c1b031b9c10734fc2cbb78ed1f104dd
 U drh
-Z 6ec74c1e47a6a671533b542ae146a0f8
+Z 4f5517f8772eb0c19d9bc59edbaff4cc
diff --git a/manifest.uuid b/manifest.uuid
index 2020e584ff..688cc99f9e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c20aca06610407c197ea50ea77c2591aacf2252a
\ No newline at end of file
+03af4c175c6ba303ec0a5be25fd42771e38f7347
\ No newline at end of file
diff --git a/src/test1.c b/src/test1.c
index 7fdf54b128..91bb1b4998 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -5574,6 +5574,93 @@ static int test_test_control(
   return TCL_OK;
 }
 
+#if SQLITE_OS_WIN
+/*
+** Information passed from the main thread into the windows file locker
+** background thread.
+*/
+struct win32FileLocker {
+  HANDLE h;           /* Handle of the file to be locked */
+  int delay1;         /* Delay before locking */
+  int delay2;         /* Delay before unlocking */
+  int ok;             /* Finished ok */
+  int err;            /* True if an error occurs */
+};
+#endif
+
+
+#if SQLITE_OS_WIN
+/*
+** The background thread that does file locking.
+*/
+static void win32_file_locker(void *pAppData){
+  struct win32FileLocker *p = (struct win32FileLocker*)pAppData;
+  if( p->delay1 ) Sleep(p->delay1);
+  if( LockFile(p->h, 0, 0, 100000000, 0) ){
+    Sleep(p->delay2);
+    UnlockFile(p->h, 0, 0, 100000000, 0);
+    p->ok = 1;
+  }else{
+    p->err = 1;
+  }
+  CloseHandle(p->h);
+  p->h = 0;
+  p->delay1 = 0;
+  p->delay2 = 0;
+}
+#endif
+
+#if SQLITE_OS_WIN
+/*
+**      lock_win32_file FILENAME DELAY1 DELAY2
+**
+** Get an exclusive manditory lock on file for DELAY2 milliseconds.
+** Wait DELAY1 milliseconds before acquiring the lock.
+*/
+static int win32_file_lock(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  static struct win32FileLocker x = { 0, 0, 0 };
+  const char *zFilename;
+  int retry = 0;
+  
+  if( objc!=4 && objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "FILENAME DELAY1 DELAY2");
+    return TCL_ERROR;
+  }
+  if( objc==1 ){
+    char zBuf[200];
+    sqlite3_snprintf(sizeof(zBuf), zBuf, "%d %d %d %d %d",
+                     x.ok, x.err, x.delay1, x.delay2, x.h);
+    Tcl_AppendResult(interp, zBuf, (char*)0);
+    return TCL_OK;
+  }
+  while( x.h && retry<10 ){
+    retry++;
+    Sleep(100);
+  }
+  if( x.h ){
+    Tcl_AppendResult(interp, "busy", (char*)0);
+    return TCL_ERROR;
+  }
+  if( Tcl_GetIntFromObj(interp, objv[2], &x.delay1) ) return TCL_ERROR;
+  if( Tcl_GetIntFromObj(interp, objv[3], &x.delay2) ) return TCL_ERROR;
+  zFilename = Tcl_GetString(objv[1]);
+  x.h = CreateFile(zFilename, GENERIC_READ|GENERIC_WRITE,
+              FILE_SHARE_READ|FILE_SHARE_WRITE, 0, OPEN_ALWAYS,
+              FILE_ATTRIBUTE_NORMAL, 0);
+  if( !x.h ){
+    Tcl_AppendResult(interp, "cannot open file: ", zFilename, (char*)0);
+    return TCL_ERROR;
+  }
+  _beginthread(win32_file_locker, 0, (void*)&x);
+  Sleep(0);
+  return TCL_OK;
+}
+#endif
 
 /*
 **      optimization_control DB OPT BOOLEAN
@@ -5754,6 +5841,9 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
      { "restore_prng_state",            restore_prng_state, 0 },
      { "reset_prng_state",              reset_prng_state,   0 },
      { "optimization_control",          optimization_control,0},
+#if SQLITE_OS_WIN
+     { "lock_win32_file",               win32_file_lock,    0 },
+#endif
      { "tcl_objproc",                   runAsObjProc,       0 },
 
      /* sqlite3_column_*() API */
diff --git a/test/win32lock.test b/test/win32lock.test
new file mode 100644
index 0000000000..a45712d173
--- /dev/null
+++ b/test/win32lock.test
@@ -0,0 +1,57 @@
+# 2011 July 11
+#
+# 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.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.  The
+# focus of this script is recovery from transient manditory locks
+# that sometimes appear on database files due to anti-virus software.
+#
+
+if {$tcl_platform(platform)!="windows"} return
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+set testprefix win32lock
+
+do_test win32lock-1.1 {
+  db eval {
+    PRAGMA cache_size=10;
+    CREATE TABLE t1(x,y);
+    INSERT INTO t1 VALUES(1,randomblob(100000));
+    INSERT INTO t1 VALUES(2,randomblob(50000));
+    INSERT INTO t1 VALUES(3,randomblob(25000));
+    INSERT INTO t1 VALUES(4,randomblob(12500));
+    SELECT x, length(y) FROM t1 ORDER BY rowid;
+  }
+} {1 100000 2 50000 3 25000 4 12500}
+
+unset -nocomplain delay1 rc msg
+set delay1 50
+set rc 0
+set old_pending_byte [sqlite3_test_control_pending_byte 0x40000000]
+while {1} {
+  sqlite3_sleep 10
+  lock_win32_file test.db 0 $::delay1
+  set rc [catch {db eval {SELECT x, length(y) FROM t1 ORDER BY rowid}} msg]
+  if {$rc} {
+    do_test win32lock-1.2-$delay1-fin {
+       set ::msg
+    } {disk I/O error}
+    break
+  } else {
+    do_test win32lock-1.2-$delay1 {
+       set ::msg
+    } {1 100000 2 50000 3 25000 4 12500}
+    incr delay1 50
+  }
+}
+sqlite3_test_control_pending_byte $old_pending_byte
+
+finish_test