diff --git a/Makefile.msc b/Makefile.msc
index 60fe09dcd1..022939f2fa 100644
--- a/Makefile.msc
+++ b/Makefile.msc
@@ -11,6 +11,23 @@ TOP = .
 #
 USE_AMALGAMATION = 1
 
+# Set this to non-0 to create and use PDBs.
+#
+SYMBOLS = 1
+
+# Set this to one of the following values to enable various debugging
+# features.  Each level includes the debugging options from the previous
+# levels.  Currently, the recognized values for DEBUG are:
+#
+# 0 == NDEBUG: Disables assert() and other runtime diagnostics.
+# 1 == Disables NDEBUG and all optimizations and then enables PDBs.
+# 2 == SQLITE_DEBUG: Enables various diagnostics messages and code.
+# 3 == SQLITE_WIN32_MALLOC_VALIDATE: Validate the Win32 native heap per call.
+# 4 == SQLITE_DEBUG_OS_TRACE: Enables output from the OSTRACE() macros.
+# 5 == SQLITE_ENABLE_IOTRACE: Enables output from the IOTRACE() macros.
+#
+DEBUG = 0
+
 # Version numbers and release number for the SQLite being compiled.
 #
 VERSION = 3.7
@@ -20,13 +37,13 @@ RELEASE = 3.7.7
 # C Compiler and options for use in building executables that
 # will run on the platform that is doing the build.
 #
-BCC = cl.exe -O2
+BCC = cl.exe
 
 # C Compile and options for use in building executables that
 # will run on the target platform.  (BCC and TCC are usually the
 # same unless your are cross-compiling.)
 #
-TCC = cl.exe -W3 -O2 -DSQLITE_OS_WIN=1 -I. -I$(TOP)\src -fp:precise
+TCC = cl.exe -W3 -DSQLITE_OS_WIN=1 -I. -I$(TOP)\src -fp:precise
 
 # The mksqlite3c.tcl and mksqlite3h.tcl scripts will pull in 
 # any extension header files by default.  For non-amalgamation
@@ -41,13 +58,39 @@ TCC = $(TCC) -I$(TOP)\ext\rtree
 # Omitting the define will cause extra debugging code to be inserted and
 # includes extra comments when "EXPLAIN stmt" is used.
 #
+!IF $(DEBUG)==0
 TCC = $(TCC) -DNDEBUG
+!ENDIF
+
+!IF $(DEBUG)>1
+TCC = $(TCC) -DSQLITE_DEBUG
+!ENDIF
+
+!IF $(DEBUG)>3
+TCC = $(TCC) -DSQLITE_DEBUG_OS_TRACE=1
+!ENDIF
+
+!IF $(DEBUG)>4
+TCC = $(TCC) -DSQLITE_ENABLE_IOTRACE
+!ENDIF
 
 #
 # Prevent warnings about "insecure" runtime library functions being used.
 #
 TCC = $(TCC) -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS
 
+#
+# Use native Win32 heap instead of malloc/free?
+#
+# TCC = $(TCC) -DSQLITE_WIN32_MALLOC=1
+
+#
+# Validate the heap on every call into the native Win32 heap subsystem?
+#
+!IF $(DEBUG)>2
+TCC = $(TCC) -DSQLITE_WIN32_MALLOC_VALIDATE=1
+!ENDIF
+
 # The locations of the Tcl header and library files.  Also, the library that
 # non-stubs enabled programs using Tcl must link against.  These variables
 # (TCLINCDIR, TCLLIBDIR, and LIBTCL) may be overridden via the environment
@@ -124,6 +167,18 @@ TCC = $(TCC) $(OPT_FEATURE_FLAGS)
 # ie.  make "OPTS=-DSQLITE_ENABLE_FOO=1 -DSQLITE_OMIT_FOO=1".
 TCC = $(TCC) $(OPTS)
 
+# If symbols are enabled, enable PDBs.
+# If debugging is enabled, disable all optimizations and enable PDBs.
+!IF $(DEBUG)>0
+TCC = $(TCC) -Od -D_DEBUG
+!ELSE
+TCC = $(TCC) -O2
+!ENDIF
+
+!IF $(DEBUG)>0 || $(SYMBOLS)!=0
+TCC = $(TCC) -Zi
+!ENDIF
+
 # libtool compile/link
 LTCOMPILE = $(TCC) -Fo$@
 LTLIB = lib.exe
@@ -138,6 +193,11 @@ LTLINKOPTS = /MACHINE:$(PLATFORM)
 LTLIBOPTS = /MACHINE:$(PLATFORM)
 !ENDIF
 
+# If debugging is enabled, enable PDBs.
+!IF $(DEBUG)>0 || $(SYMBOLS)!=0
+LTLINKOPTS = $(LTLINKOPTS) /DEBUG
+!ENDIF
+
 # nawk compatible awk.
 NAWK = gawk.exe
 
diff --git a/manifest b/manifest
index 592d23a24a..d9d94740e2 100644
--- a/manifest
+++ b/manifest
@@ -1,9 +1,9 @@
-C Create\sa\snew\spager\stype,\sPAGER_SORTER,\sfor\suse\sin\sthe\sexternal\smerge\ssort.\nSuch\spagers\sare\salways\sheld\sin\smemory\sbut\sdo\sreport\swhen\sthey\sare\sunder\nmemory\spressure\sby\scalling\spagerStress.
-D 2011-08-26T00:34:45.360
+C Merge\sWin32\snative\sheap\ssupport\sinto\strunk.
+D 2011-08-26T11:18:44.284
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 8c930e7b493d59099ea1304bd0f2aed152eb3315
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc 386444f1e1a1536d19a426030d93fd6e03b7d3b5
+F Makefile.msc 55fe94bf23b4c1ff035f19b0ae2ea486350f8d01
 F Makefile.vxworks c85ec1d8597fe2f7bc225af12ac1666e21379151
 F README cd04a36fbc7ea56932a4052d7d0b7f09f27c33d6
 F VERSION f724de7326e87b7f3b0a55f16ef4b4d993680d54
@@ -166,7 +166,7 @@ F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h 65a897143b64667d23ed329a7984b9b405accb58
 F src/os_os2.c 4a75888ba3dfc820ad5e8177025972d74d7f2440
 F src/os_unix.c 1a34ca3794ced80e4a4ebcc3ba1f4c516762e534
-F src/os_win.c 19fa09046f1f86590a188abdcf5630b8fe8279cf
+F src/os_win.c 86bcb5bd0386c761c764c3383879469346da3a14
 F src/pager.c 817f7f7140c9fa2641f28e6330e924708ddd870d
 F src/pager.h 2bab1b2ea4eac58663b5833e3522e36b5ff63447
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
@@ -183,7 +183,7 @@ F src/select.c d219c4b68d603cc734b6f9b1e2780fee12a1fa0d
 F src/shell.c bbe7818ff5bc8614105ceb81ad67b8bdc0b671dd
 F src/sqlite.h.in 0a6c9c23337fd1352c5c75a613ff9533aa7d91cb
 F src/sqlite3ext.h 1a1a4f784aa9c3b00edd287940197de52487cd93
-F src/sqliteInt.h 18876859c6a60fd42b4e3772229387390702f096
+F src/sqliteInt.h 42e60144648d32e5a6c9994b2baa58b9cf8db69b
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -918,7 +918,7 @@ F test/where9.test 24f19ad14bb1b831564ced5273e681e495662848
 F test/whereA.test 24c234263c8fe358f079d5e57d884fb569d2da0a
 F test/whereB.test 0def95db3bdec220a731c7e4bec5930327c1d8c5
 F test/wherelimit.test 5e9fd41e79bb2b2d588ed999d641d9c965619b31
-F test/win32lock.test d60b39c53c68617524429be27bf239f0b11673f2
+F test/win32lock.test b2a539e85ae6b2d78475e016a9636b4451dc7fb9
 F test/zeroblob.test caaecfb4f908f7bc086ed238668049f96774d688
 F tool/build-shell.sh 12aa4391073a777fcb6dcc490b219a018ae98bac
 F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
@@ -961,7 +961,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
 F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh b7fdb2cc525f5ef4fa43c80e771636dd3690f9d2
-P 2c443d47ecee7b43a89f0a4bf299c46c66e3f80d
-R 5271767b893f002dc634ff718e14ca01
-U drh
-Z 986c77c3e73f3db4a3199ce94583c644
+P c71d73201d950355862dd8d5de142c9673888755 5ed7633d41b99929309a7e13d37375a4fdae43b3
+R 6db87d8333d6edb6b791bc23dadc42e1
+U mistachkin
+Z 81e8aedab83fc3e19b6d4ef38c1919d2
diff --git a/manifest.uuid b/manifest.uuid
index d151ff9b84..a5277be89e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c71d73201d950355862dd8d5de142c9673888755
\ No newline at end of file
+5238a74987507f27af4080e2842f53e049b5b111
\ No newline at end of file
diff --git a/src/os_win.c b/src/os_win.c
index 60b8701244..02a7a0c622 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -119,6 +119,76 @@ struct winFile {
 #endif
 };
 
+/*
+ * If compiled with SQLITE_WIN32_MALLOC on Windows, we will use the
+ * various Win32 API heap functions instead of our own.
+ */
+#ifdef SQLITE_WIN32_MALLOC
+/*
+ * The initial size of the Win32-specific heap.  This value may be zero.
+ */
+#ifndef SQLITE_WIN32_HEAP_INIT_SIZE
+#  define SQLITE_WIN32_HEAP_INIT_SIZE ((SQLITE_DEFAULT_CACHE_SIZE) * \
+                                       (SQLITE_DEFAULT_PAGE_SIZE) + 4194304)
+#endif
+
+/*
+ * The maximum size of the Win32-specific heap.  This value may be zero.
+ */
+#ifndef SQLITE_WIN32_HEAP_MAX_SIZE
+#  define SQLITE_WIN32_HEAP_MAX_SIZE  (0)
+#endif
+
+/*
+ * The extra flags to use in calls to the Win32 heap APIs.  This value may be
+ * zero for the default behavior.
+ */
+#ifndef SQLITE_WIN32_HEAP_FLAGS
+#  define SQLITE_WIN32_HEAP_FLAGS     (0)
+#endif
+
+/*
+** The winMemData structure stores information required by the Win32-specific
+** sqlite3_mem_methods implementation.
+*/
+typedef struct winMemData winMemData;
+struct winMemData {
+#ifndef NDEBUG
+  u32 magic;    /* Magic number to detect structure corruption. */
+#endif
+  HANDLE hHeap; /* The handle to our heap. */
+  BOOL bOwned;  /* Do we own the heap (i.e. destroy it on shutdown)? */
+};
+
+#ifndef NDEBUG
+#define WINMEM_MAGIC     0x42b2830b
+#endif
+
+static struct winMemData win_mem_data = {
+#ifndef NDEBUG
+  WINMEM_MAGIC,
+#endif
+  NULL, FALSE
+};
+
+#ifndef NDEBUG
+#define winMemAssertMagic() assert( win_mem_data.magic==WINMEM_MAGIC )
+#else
+#define winMemAssertMagic()
+#endif
+
+#define winMemGetHeap() win_mem_data.hHeap
+
+static void *winMemMalloc(int nBytes);
+static void winMemFree(void *pPrior);
+static void *winMemRealloc(void *pPrior, int nBytes);
+static int winMemSize(void *p);
+static int winMemRoundup(int n);
+static int winMemInit(void *pAppData);
+static void winMemShutdown(void *pAppData);
+
+const sqlite3_mem_methods *sqlite3MemGetWin32(void);
+#endif /* SQLITE_WIN32_MALLOC */
 
 /*
 ** Forward prototypes.
@@ -171,6 +241,188 @@ static int sqlite3_os_type = 0;
   }
 #endif /* SQLITE_OS_WINCE */
 
+#ifdef SQLITE_WIN32_MALLOC
+/*
+** Allocate nBytes of memory.
+*/
+static void *winMemMalloc(int nBytes){
+  HANDLE hHeap;
+  void *p;
+
+  winMemAssertMagic();
+  hHeap = winMemGetHeap();
+  assert( hHeap!=0 );
+  assert( hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#endif
+  assert( nBytes>=0 );
+  p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
+  if( !p ){
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapAlloc %u bytes (%d), heap=%p",
+        nBytes, GetLastError(), (void*)hHeap);
+  }
+  return p;
+}
+
+/*
+** Free memory.
+*/
+static void winMemFree(void *pPrior){
+  HANDLE hHeap;
+
+  winMemAssertMagic();
+  hHeap = winMemGetHeap();
+  assert( hHeap!=0 );
+  assert( hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
+#endif
+  if( !pPrior ) return; /* Passing NULL to HeapFree is undefined. */
+  if( !HeapFree(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) ){
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapFree block %p (%d), heap=%p",
+        pPrior, GetLastError(), (void*)hHeap);
+  }
+}
+
+/*
+** Change the size of an existing memory allocation
+*/
+static void *winMemRealloc(void *pPrior, int nBytes){
+  HANDLE hHeap;
+  void *p;
+
+  winMemAssertMagic();
+  hHeap = winMemGetHeap();
+  assert( hHeap!=0 );
+  assert( hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior) );
+#endif
+  assert( nBytes>=0 );
+  if( !pPrior ){
+    p = HeapAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, (SIZE_T)nBytes);
+  }else{
+    p = HeapReAlloc(hHeap, SQLITE_WIN32_HEAP_FLAGS, pPrior, (SIZE_T)nBytes);
+  }
+  if( !p ){
+    sqlite3_log(SQLITE_NOMEM, "failed to %s %u bytes (%d), heap=%p",
+        pPrior ? "HeapReAlloc" : "HeapAlloc", nBytes, GetLastError(),
+        (void*)hHeap);
+  }
+  return p;
+}
+
+/*
+** Return the size of an outstanding allocation, in bytes.
+*/
+static int winMemSize(void *p){
+  HANDLE hHeap;
+  SIZE_T n;
+
+  winMemAssertMagic();
+  hHeap = winMemGetHeap();
+  assert( hHeap!=0 );
+  assert( hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+  assert ( HeapValidate(hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#endif
+  if( !p ) return 0;
+  n = HeapSize(hHeap, SQLITE_WIN32_HEAP_FLAGS, p);
+  if( n==(SIZE_T)-1 ){
+    sqlite3_log(SQLITE_NOMEM, "failed to HeapSize block %p (%d), heap=%p",
+        p, GetLastError(), (void*)hHeap);
+    return 0;
+  }
+  return (int)n;
+}
+
+/*
+** Round up a request size to the next valid allocation size.
+*/
+static int winMemRoundup(int n){
+  return n;
+}
+
+/*
+** Initialize this module.
+*/
+static int winMemInit(void *pAppData){
+  winMemData *pWinMemData = (winMemData *)pAppData;
+
+  if( !pWinMemData ) return SQLITE_ERROR;
+  assert( pWinMemData->magic==WINMEM_MAGIC );
+  if( !pWinMemData->hHeap ){
+    pWinMemData->hHeap = HeapCreate(SQLITE_WIN32_HEAP_FLAGS,
+                                    SQLITE_WIN32_HEAP_INIT_SIZE,
+                                    SQLITE_WIN32_HEAP_MAX_SIZE);
+    if( !pWinMemData->hHeap ){
+      sqlite3_log(SQLITE_NOMEM,
+          "failed to HeapCreate (%d), flags=%u, initSize=%u, maxSize=%u",
+          GetLastError(), SQLITE_WIN32_HEAP_FLAGS, SQLITE_WIN32_HEAP_INIT_SIZE,
+          SQLITE_WIN32_HEAP_MAX_SIZE);
+      return SQLITE_NOMEM;
+    }
+    pWinMemData->bOwned = TRUE;
+  }
+  assert( pWinMemData->hHeap!=0 );
+  assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+  assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#endif
+  return SQLITE_OK;
+}
+
+/*
+** Deinitialize this module.
+*/
+static void winMemShutdown(void *pAppData){
+  winMemData *pWinMemData = (winMemData *)pAppData;
+
+  if( !pWinMemData ) return;
+  if( pWinMemData->hHeap ){
+    assert( pWinMemData->hHeap!=INVALID_HANDLE_VALUE );
+#ifdef SQLITE_WIN32_MALLOC_VALIDATE
+    assert( HeapValidate(pWinMemData->hHeap, SQLITE_WIN32_HEAP_FLAGS, NULL) );
+#endif
+    if( pWinMemData->bOwned ){
+      if( !HeapDestroy(pWinMemData->hHeap) ){
+        sqlite3_log(SQLITE_NOMEM, "failed to HeapDestroy (%d), heap=%p",
+            GetLastError(), (void*)pWinMemData->hHeap);
+      }
+      pWinMemData->bOwned = FALSE;
+    }
+    pWinMemData->hHeap = NULL;
+  }
+}
+
+/*
+** Populate the low-level memory allocation function pointers in
+** sqlite3GlobalConfig.m with pointers to the routines in this file. The
+** arguments specify the block of memory to manage.
+**
+** This routine is only called by sqlite3_config(), and therefore
+** is not required to be threadsafe (it is not).
+*/
+const sqlite3_mem_methods *sqlite3MemGetWin32(void){
+  static const sqlite3_mem_methods winMemMethods = {
+    winMemMalloc,
+    winMemFree,
+    winMemRealloc,
+    winMemSize,
+    winMemRoundup,
+    winMemInit,
+    winMemShutdown,
+    &win_mem_data
+  };
+  return &winMemMethods;
+}
+
+void sqlite3MemSetDefault(void){
+  sqlite3_config(SQLITE_CONFIG_MALLOC, sqlite3MemGetWin32());
+}
+#endif /* SQLITE_WIN32_MALLOC */
+
 /*
 ** Convert a UTF-8 string to microsoft unicode (UTF-16?). 
 **
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index c97499b30d..591d5f0383 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -147,19 +147,25 @@
 ** specify which memory allocation subsystem to use.
 **
 **     SQLITE_SYSTEM_MALLOC          // Use normal system malloc()
+**     SQLITE_WIN32_MALLOC           // Use Win32 native heap API
 **     SQLITE_MEMDEBUG               // Debugging version of system malloc()
 **
+** On Windows, if the SQLITE_WIN32_MALLOC_VALIDATE macro is defined and the
+** assert() macro is enabled, each call into the Win32 native heap subsystem
+** will cause HeapValidate to be called.  If heap validation should fail, an
+** assertion will be triggered.
+**
 ** (Historical note:  There used to be several other options, but we've
 ** pared it down to just these two.)
 **
 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
 ** the default.
 */
-#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)>1
+#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)>1
 # error "At most one of the following compile-time configuration options\
  is allows: SQLITE_SYSTEM_MALLOC, SQLITE_MEMDEBUG"
 #endif
-#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_MEMDEBUG)==0
+#if defined(SQLITE_SYSTEM_MALLOC)+defined(SQLITE_WIN32_MALLOC)+defined(SQLITE_MEMDEBUG)==0
 # define SQLITE_SYSTEM_MALLOC 1
 #endif
 
diff --git a/test/win32lock.test b/test/win32lock.test
index 7fed2e0c08..d014be4d2c 100644
--- a/test/win32lock.test
+++ b/test/win32lock.test
@@ -69,6 +69,10 @@ while {1} {
   }
   if {[llength $win32_lock_ok] && [llength $win32_lock_error]} break
   incr delay1 25
+  if {$delay1 > 12500} {
+    puts "Timed out waiting for \"ok\" and \"error\" results."
+    break
+  }
   sqlite3_sleep 10
 }
 
@@ -113,11 +117,16 @@ while {1} {
   }
   if {[llength $win32_lock_ok] && [llength $win32_lock_error]} break
   incr delay1 1
+  if {$delay1 > 500} {
+    puts "Timed out waiting for \"ok\" and \"error\" results."
+    break
+  }
   sqlite3_sleep 10
 }
 
 file_control_win32_av_retry db 10 25
 sqlite3_test_control_pending_byte $old_pending_byte
+db close
 sqlite3_shutdown
 test_sqlite3_log 
 sqlite3_initialize