diff --git a/Makefile.msc b/Makefile.msc
index 61e5102607..119468a92d 100644
--- a/Makefile.msc
+++ b/Makefile.msc
@@ -1319,6 +1319,10 @@ testfixture.exe:	$(TESTFIXTURE_SRC) $(LIBRESOBJS) $(HDR)
 		$(TESTFIXTURE_SRC) \
 		/link $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)
 
+extensiontest: testfixture.exe testloadext.dll
+	.\testfixture.exe $(TOP)\test\loadext.test
+	.\testfixture.exe $(TOP)\test\loadext2.test
+
 fulltest:	testfixture.exe sqlite3.exe
 	.\testfixture.exe $(TOP)\test\all.test
 
@@ -1345,6 +1349,12 @@ sqlite3_analyzer.exe:	sqlite3_analyzer.c $(LIBRESOBJS)
 	$(LTLINK) -DBUILD_sqlite -DTCLSH=2 -I$(TCLINCDIR) sqlite3_analyzer.c \
 		/link $(LTLINKOPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LTLIBS) $(TLIBS)
 
+testloadext.lo:	$(TOP)\src\test_loadext.c
+	$(LTCOMPILE) -c $(TOP)\src\test_loadext.c
+
+testloadext.dll: testloadext.lo
+	$(LD) $(LDFLAGS) $(LTLINKOPTS) $(LTLIBPATHS) /DLL /OUT:$@ testloadext.lo
+
 showdb.exe:	$(TOP)\tool\showdb.c $(SQLITE3C)
 	$(LTLINK) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -Fe$@ \
 		$(TOP)\tool\showdb.c $(SQLITE3C)
@@ -1371,6 +1381,7 @@ clean:
 	-rmdir /Q/S tsrc
 	del /Q .target_source
 	del /Q tclsqlite3.exe tclsqlite3.exp
+	del /Q testloadext.dll testloadext.exp
 	del /Q testfixture.exe testfixture.exp test.db
 	del /Q sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
 	del /Q sqlite3.c sqlite3-*.c
diff --git a/manifest b/manifest
index 4ed19202d6..fc4f0247aa 100644
--- a/manifest
+++ b/manifest
@@ -1,9 +1,9 @@
-C Better\sloadable\sextension\shandling\sin\sthe\sWin32\sVFS\swhen\scompiled\sfor\sCygwin.
-D 2014-02-21T05:44:18.393
+C Merge\supdates\sfrom\strunk.
+D 2014-02-24T21:23:07.956
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc 371a17ef9cd011b103cfa1964119a8528f5427c9
+F Makefile.msc 4b39e17eb244d2fd3fb825d896380b38b782e69a
 F Makefile.vxworks db21ed42a01d5740e656b16f92cb5d8d5e5dd315
 F README.md 64f270c43c38c46de749e419c22f0ae2f4499fe8
 F VERSION 0dc30ad5cf90736d5fd9e540c9f05c542658abe7
@@ -191,7 +191,7 @@ F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c c0c990fcaddff810ea277b4fb5d9138603dd5d4b
 F src/mem2.c dce31758da87ec2cfa52ba4c5df1aed6e07d8e8f
 F src/mem3.c 61c9d47b792908c532ca3a62b999cf21795c6534
-F src/mem5.c 19d9271cb936742707b6118ed44d779657c7c511
+F src/mem5.c aeb019f271ea53de83d651ec526877e6ba863450
 F src/memjournal.c 0683aac6cab6ec2b5374c0db37c0deb2436a3785
 F src/mutex.c d3b66a569368015e0fcb1ac15f81c119f504d3bc
 F src/mutex.h 5bc526e19dccc412b7ff04642f6fdad3fdfdabea
@@ -203,7 +203,7 @@ F src/os.c 1b147e4cf7cc39e618115c14a086aed44bc91ace
 F src/os.h 4a46270a64e9193af4a0aaa3bc2c66dc07c29b3f
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
 F src/os_unix.c 18f7f95dc6bcb9cf4d4a238d8e2de96611bc2ae5
-F src/os_win.c 23bd567f897b8934096ee7ce51b21ba43aa94ec7
+F src/os_win.c 9ce043722f5d959c52c9a751e5c960602de0927b
 F src/pager.c 0ffa313a30ed6d061d9c6601b7b175cc50a1cab7
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y 2613ca5d609c2f3d71dd297351f010bcec16e1e0
@@ -249,7 +249,7 @@ F src/test_init.c 66b33120ffe9cd853b5a905ec850d51151337b32
 F src/test_intarray.c 87847c71c3c36889c0bcc9c4baf9d31881665d61
 F src/test_intarray.h 2ece66438cfd177b78d1bfda7a4180cd3a10844d
 F src/test_journal.c f5c0a05b7b3d5930db769b5ee6c3766dc2221a64
-F src/test_loadext.c df586c27176e3c2cb2e099c78da67bf14379a56e
+F src/test_loadext.c a5251f956ab6af21e138dc1f9c0399394a510cb4
 F src/test_malloc.c 1ff5b1243d96124c9a180f3b89424820a1f337f3
 F src/test_multiplex.c 9f304bf04170c91c0318238d512df2da039eb1c8
 F src/test_multiplex.h 110a8c4d356e0aa464ca8730375608a9a0b61ae1
@@ -277,11 +277,11 @@ F src/update.c 5b3e74a03b3811e586b4f2b4cbd7c49f01c93115
 F src/utf.c 6fc6c88d50448c469c5c196acf21617a24f90269
 F src/util.c c46c90459ef9bdc0c6c73803cf4c55425b4771cf
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
-F src/vdbe.c c5ff7b384ed108be747220d4c47fcea6a36b062b
-F src/vdbe.h 6c703ccef97f4504bd0d79cc09180185a60ae8ad
+F src/vdbe.c 6c8f28911e702151c8ef03c568db5a066d3a85d4
+F src/vdbe.h 147027d6e8e667a63e87177a38e2b42c71fdacf8
 F src/vdbeInt.h 5286af9067cabdb8ba57b87c0c988a931be6c6c8
 F src/vdbeapi.c 5bc41aaea448a7fc250902c418f1795859be3820
-F src/vdbeaux.c 0e01d6fda149c689039caadb8c89b20abb58e21d
+F src/vdbeaux.c 8b8eeb3cd89e4b3d4f40186344915b49b7c1c0f7
 F src/vdbeblob.c d939997de046b8fcc607cfee4248f3d33dbcca50
 F src/vdbemem.c 06603e8e9d2f3247b68c6bbe4bd37fb6721b5bda
 F src/vdbesort.c 9d83601f9d6243fe70dd0169a2820c5ddfd48147
@@ -647,7 +647,7 @@ F test/laststmtchanges.test ae613f53819206b3222771828d024154d51db200
 F test/like.test e191e536d0fcd722a6b965e7cd1ee0bfd12a5991
 F test/like2.test 3b2ee13149ba4a8a60b59756f4e5d345573852da
 F test/limit.test cc0ab63385239b63c72452b0e93700bf5e8f0b99
-F test/loadext.test 92e6dfefd1229c3ef4aaabd87419efd8fa57a7a5
+F test/loadext.test 648cb95f324d1775c54a55c12271b2d1156b633b
 F test/loadext2.test 0408380b57adca04004247179837a18e866a74f7
 F test/lock.test 87af515b0c4cf928576d0f89946d67d7c265dfb4
 F test/lock2.test 5242d8ac4e2d59c403aebff606af449b455aceff
@@ -1064,7 +1064,7 @@ F test/walhook.test ed00a40ba7255da22d6b66433ab61fab16a63483
 F test/walmode.test 4022fe03ae6e830583672caa101f046438a0473c
 F test/walnoshm.test 84ca10c544632a756467336b7c3b864d493ee496
 F test/walpersist.test 8c6b7e3ec1ba91b5e4dc4e0921d6d3f87cd356a6
-F test/walro.test 6cc247a0cc9b36aeea2057dd28a922a1cdfbd630
+F test/walro.test 34422d1d95aaff0388f0791ec20edb34e2a3ed57
 F test/walshared.test 0befc811dcf0b287efae21612304d15576e35417
 F test/walslow.test e7be6d9888f83aa5d3d3c7c08aa9b5c28b93609a
 F test/walthread.test de8dbaf6d9e41481c460ba31ca61e163d7348f8e
@@ -1151,10 +1151,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P b46d4e8923e6e367412bba7aeac07039bbcbabd1
-R a7d693d1ea11a2ee85a54f6ea757a9d1
-T *branch * cygDlOpen
-T *sym-cygDlOpen *
-T -sym-trunk *
+P 6676475c47558a52cb2632e92a541e13d143b2dc 53081e7202fb55f792a78e73627466eb0200f11c
+R 18f77ade6087ed733fbdb268f6f34961
 U mistachkin
-Z 4b80816c39a01dfdffbdf857b2bcb9b9
+Z 803bfaab7aa1ae283bf7c1240bdf5b59
diff --git a/manifest.uuid b/manifest.uuid
index b559183c43..edfc0c8182 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6676475c47558a52cb2632e92a541e13d143b2dc
\ No newline at end of file
+854d410ad3a2bb3af5465d933ac9535fe3f22bfe
\ No newline at end of file
diff --git a/src/mem5.c b/src/mem5.c
index 4674ec68f5..5d75611a32 100644
--- a/src/mem5.c
+++ b/src/mem5.c
@@ -275,6 +275,12 @@ static void *memsys5MallocUnsafe(int nByte){
   if( mem5.maxCount<mem5.currentCount ) mem5.maxCount = mem5.currentCount;
   if( mem5.maxOut<mem5.currentOut ) mem5.maxOut = mem5.currentOut;
 
+#ifdef SQLITE_DEBUG
+  /* Make sure the allocated memory does not assume that it is set to zero
+  ** or retains a value from a previous allocation */
+  memset(&mem5.zPool[i*mem5.szAtom], 0xAA, iFullSz);
+#endif
+
   /* Return a pointer to the allocated memory. */
   return (void*)&mem5.zPool[i*mem5.szAtom];
 }
@@ -332,6 +338,13 @@ static void memsys5FreeUnsafe(void *pOld){
     }
     size *= 2;
   }
+
+#ifdef SQLITE_DEBUG
+  /* Overwrite freed memory with the 0x55 bit pattern to verify that it is
+  ** not used after being freed */
+  memset(&mem5.zPool[iBlock*mem5.szAtom], 0x55, size);
+#endif
+
   memsys5Link(iBlock, iLogsize);
 }
 
diff --git a/src/os_win.c b/src/os_win.c
index 27f2337287..e8b702a6d7 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -5135,10 +5135,6 @@ static int winFullPathname(
 ** Interfaces for opening a shared library, finding entry points
 ** within the shared library, and closing the shared library.
 */
-/*
-** Interfaces for opening a shared library, finding entry points
-** within the shared library, and closing the shared library.
-*/
 static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
   HANDLE h;
 #if defined(__CYGWIN__)
@@ -5146,10 +5142,12 @@ static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
   char *zFull = sqlite3MallocZero( nFull );
   void *zConverted = 0;
   if( zFull==0 ){
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
     return 0;
   }
   if( winFullPathname(pVfs, zFilename, nFull, zFull)!=SQLITE_OK ){
     sqlite3_free(zFull);
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
     return 0;
   }
   zConverted = winConvertFromUtf8Filename(zFull);
@@ -5159,6 +5157,7 @@ static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
   UNUSED_PARAMETER(pVfs);
 #endif
   if( zConverted==0 ){
+    OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)0));
     return 0;
   }
   if( osIsNT() ){
@@ -5173,6 +5172,7 @@ static void *winDlOpen(sqlite3_vfs *pVfs, const char *zFilename){
     h = osLoadLibraryA((char*)zConverted);
   }
 #endif
+  OSTRACE(("DLOPEN name=%s, handle=%p\n", zFilename, (void*)h));
   sqlite3_free(zConverted);
   return (void*)h;
 }
@@ -5181,12 +5181,17 @@ static void winDlError(sqlite3_vfs *pVfs, int nBuf, char *zBufOut){
   winGetLastErrorMsg(osGetLastError(), nBuf, zBufOut);
 }
 static void (*winDlSym(sqlite3_vfs *pVfs,void *pH,const char *zSym))(void){
+  FARPROC pProc;
   UNUSED_PARAMETER(pVfs);
-  return (void(*)(void))osGetProcAddressA((HANDLE)pH, zSym);
+  pProc = osGetProcAddressA((HANDLE)pH, zSym);
+  OSTRACE(("DLSYM handle=%p, symbol=%s, proc=%p\n",
+           (void*)pH, zSym, (void*)pProc));
+  return (void(*)(void))pProc;
 }
 static void winDlClose(sqlite3_vfs *pVfs, void *pHandle){
   UNUSED_PARAMETER(pVfs);
   osFreeLibrary((HANDLE)pHandle);
+  OSTRACE(("DLCLOSE handle=%p\n", (void*)pHandle));
 }
 #else /* if SQLITE_OMIT_LOAD_EXTENSION is defined: */
   #define winDlOpen  0
diff --git a/src/test_loadext.c b/src/test_loadext.c
index 1137e3a9aa..5a1f46da9c 100644
--- a/src/test_loadext.c
+++ b/src/test_loadext.c
@@ -91,6 +91,9 @@ static void statusFunc(
 /*
 ** Extension load function.
 */
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
 int testloadext_init(
   sqlite3 *db, 
   char **pzErrMsg, 
@@ -109,6 +112,9 @@ int testloadext_init(
 /*
 ** Another extension entry point. This one always fails.
 */
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
 int testbrokenext_init(
   sqlite3 *db, 
   char **pzErrMsg, 
diff --git a/src/vdbe.c b/src/vdbe.c
index 2253af4719..5ab0127658 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -492,7 +492,6 @@ int sqlite3VdbeExec(
   i64 lastRowid = db->lastRowid;  /* Saved value of the last insert ROWID */
 #ifdef VDBE_PROFILE
   u64 start;                 /* CPU clock count at start of opcode */
-  int origPc;                /* Program counter at start of opcode */
 #endif
   /*** INSERT STACK UNION HERE ***/
 
@@ -554,7 +553,6 @@ int sqlite3VdbeExec(
     assert( pc>=0 && pc<p->nOp );
     if( db->mallocFailed ) goto no_mem;
 #ifdef VDBE_PROFILE
-    origPc = pc;
     start = sqlite3Hwtime();
 #endif
     nVmStep++;
@@ -6275,10 +6273,6 @@ default: {          /* This is really OP_Noop and OP_Explain */
       u64 elapsed = sqlite3Hwtime() - start;
       pOp->cycles += elapsed;
       pOp->cnt++;
-#if 0
-        fprintf(stdout, "%10llu ", elapsed);
-        sqlite3VdbePrintOp(stdout, origPc, &aOp[origPc]);
-#endif
     }
 #endif
 
diff --git a/src/vdbe.h b/src/vdbe.h
index 44cd9123aa..66c69eec23 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -65,7 +65,7 @@ struct VdbeOp {
   char *zComment;          /* Comment to improve readability */
 #endif
 #ifdef VDBE_PROFILE
-  int cnt;                 /* Number of times this instruction was executed */
+  u32 cnt;                 /* Number of times this instruction was executed */
   u64 cycles;              /* Total time spent executing this instruction */
 #endif
 #ifdef SQLITE_VDBE_COVERAGE
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 89bb8975a5..ef70f8ae3f 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2580,11 +2580,13 @@ int sqlite3VdbeReset(Vdbe *p){
         if( pc!='\n' ) fprintf(out, "\n");
       }
       for(i=0; i<p->nOp; i++){
-        fprintf(out, "%6d %10lld %8lld ",
+        char zHdr[100];
+        sqlite3_snprintf(sizeof(zHdr), zHdr, "%6u %12llu %8llu ",
            p->aOp[i].cnt,
            p->aOp[i].cycles,
            p->aOp[i].cnt>0 ? p->aOp[i].cycles/p->aOp[i].cnt : 0
         );
+        fprintf(out, "%s", zHdr);
         sqlite3VdbePrintOp(out, i, &p->aOp[i]);
       }
       fclose(out);
diff --git a/test/loadext.test b/test/loadext.test
index 0d5b841980..7ba4c0cf77 100644
--- a/test/loadext.test
+++ b/test/loadext.test
@@ -66,6 +66,12 @@ if {$::tcl_platform(os) eq "Darwin"} {
   set dlerror_nosymbol   {dlsym(XXX, %2$s): symbol not found}
 }
 
+if {$::tcl_platform(platform) eq "windows"} {
+  set dlerror_nosuchfile {The specified module could not be found.*}
+  set dlerror_notadll    {%%1 is not a valid Win32 application.*}
+  set dlerror_nosymbol   {The specified procedure could not be found.*}
+}
+
 # Make sure the test extension actually exists.  If it does not
 # exist, try to create it.  If unable to create it, then skip this
 # test file.
@@ -167,7 +173,7 @@ do_test loadext-2.3 {
     regsub {0x[1234567890abcdefABCDEF]*} $msg XXX msg
   }
   list $rc $msg
-} [list 1 [format $dlerror_nosymbol $testextension icecream]]
+} /[list 1 [format $dlerror_nosymbol $testextension icecream]]/
 
 # Try to load an extension for which the entry point fails (returns non-zero) 
 #
@@ -267,10 +273,17 @@ do_malloc_test loadext-5 -tclprep {
 } -tclbody {
   if {[autoinstall_test_functions]==7} {error "out of memory"}
 }
-do_malloc_test loadext-6 -tclbody {
-  db enable_load_extension 1
-  sqlite3_load_extension db $::testextension testloadext_init
+
+# On Windows, this malloc test must be skipped because the winDlOpen
+# function itself can fail due to "out of memory" conditions.
+#
+if {$::tcl_platform(platform) ne "windows"} {
+  do_malloc_test loadext-6 -tclbody {
+    db enable_load_extension 1
+    sqlite3_load_extension db $::testextension testloadext_init
+  }
 }
+
 autoinstall_test_functions
 
 finish_test
diff --git a/test/walro.test b/test/walro.test
index f1ed275a1d..6d920b1e24 100644
--- a/test/walro.test
+++ b/test/walro.test
@@ -32,9 +32,6 @@ ifcapable !wal {
 }
 
 do_multiclient_test tn {
-  # Do not run tests with the connections in the same process.
-  #
-  if {$tn==2} continue
   
   # Close all connections and delete the database.
   #
@@ -43,6 +40,10 @@ do_multiclient_test tn {
   code3 { db3 close }
   forcedelete test.db
   forcedelete walro
+  
+  # Do not run tests with the connections in the same process.
+  #
+  if {$tn==2} continue
 
   foreach c {code1 code2 code3} {
     $c {
@@ -232,9 +233,6 @@ forcedelete test.db
 # database file while a checkpoint operation is ongoing.
 #
 do_multiclient_test tn {
-  # Do not run tests with the connections in the same process.
-  #
-  if {$tn==2} continue
   
   # Close all connections and delete the database.
   #
@@ -243,6 +241,10 @@ do_multiclient_test tn {
   code3 { db3 close }
   forcedelete test.db
   forcedelete walro
+  
+  # Do not run tests with the connections in the same process.
+  #
+  if {$tn==2} continue
 
   foreach c {code1 code2 code3} {
     $c {