diff --git a/manifest b/manifest
index ede507e232..7d0c619625 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Allow\sthe\sjournal_size_limit\sto\sbe\slarger\sthan\s2147483647\sbytes.\s(CVS\s6449)
-D 2009-04-04T16:02:32
+C Additional\scode\sto\smake\ssure\sand\sto\sassert\sthat\smemory\sallocations\shave\n8-byte\salignment.\s\sTicket\s#3777.\s(CVS\s6450)
+D 2009-04-05T12:22:09
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 583e87706abc3026960ed759aff6371faf84c211
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -103,7 +103,7 @@ F src/auth.c c8b2ab5c8bad4bd90ed7c294694f48269162c627
 F src/backup.c 0082d0e5a63f04e88faee0dff0a7d63d3e92a78d
 F src/bitvec.c ef370407e03440b0852d05024fb016b14a471d3d
 F src/btmutex.c 341502bc496dc0840dcb00cde65680fb0e85c3ab
-F src/btree.c f4fdf5359f910dd9ac8d7bd92a67dae072b75f81
+F src/btree.c 457a71a1ebf490d5079ebe36d0213a8025d621a8
 F src/btree.h 8007018c1753944790c39610280894ab280210b8
 F src/btreeInt.h df64030d632f8c8ac217ed52e8b6b3eacacb33a5
 F src/build.c 72357fd75ef036d0afbf1756edab6d62c56fcf4b
@@ -129,7 +129,7 @@ F src/mem1.c e6d5c23941288df8191b8a98c28e3f57771e2270
 F src/mem2.c d02bd6a5b34f2d59012a852615621939d9c09548
 F src/mem3.c 67153ec933e08b70714055e872efb58a6b287939
 F src/mem5.c 838309b521c96a2a34507f74a5a739d28de4aac6
-F src/memjournal.c d6f5cc35cdba795fc3d39812c5669cc012b5ed6f
+F src/memjournal.c 1a987d078e7446a44417a1a6a01f80b48cf65b93
 F src/mutex.c 5e2ea0e0490a3567dc08a014bcee748c0cea727f
 F src/mutex.h 9e686e83a88838dac8b9c51271c651e833060f1e
 F src/mutex_noop.c f5a07671f25a1a9bd7c10ad7107bc2585446200f
@@ -143,7 +143,7 @@ F src/os_common.h 8c61457df58f1a4bd5f5adc3e90e01b37bf7afbc
 F src/os_os2.c bed77dc26e3a95ce4a204936b9a1ca6fe612fcc5
 F src/os_unix.c 5d667f24615043c937a138faaed5f3e93b8619b0
 F src/os_win.c 524fe4c31c469531191857e8036ef59bfb52d684
-F src/pager.c a8b53f7e4a821d5bc2e01477a5f10c9348ce1d7b
+F src/pager.c 1df277b7c78f780df119c9e2ddea6690979489c5
 F src/pager.h 0c9f3520c00d8a3b8e792ca56c9a11b6b02b4b0f
 F src/parse.y 070215cf461ab917c23253a9cbf0903f2b0d8f19
 F src/pcache.c 395f752a13574120bd7513a400ba02a265aaa76d
@@ -159,7 +159,7 @@ F src/select.c 462d9671e91accd983110fa38674be0d2a3daa66
 F src/shell.c 0a11f831603f17fea20ca97133c0f64e716af4a7
 F src/sqlite.h.in 59905c98fd40b3eb3c9a939a113858c75009b7b6
 F src/sqlite3ext.h 1db7d63ab5de4b3e6b83dd03d1a4e64fef6d2a17
-F src/sqliteInt.h 22114af78e17ab06b4ccd3b3f7db8ab14b5f2bb9
+F src/sqliteInt.h d1239060599bc45ed9e4668cb7759e6c433dd5ab
 F src/sqliteLimit.h ffe93f5a0c4e7bd13e70cd7bf84cfb5c3465f45d
 F src/status.c 237b193efae0cf6ac3f0817a208de6c6c6ef6d76
 F src/table.c 332ab0ea691e63862e2a8bdfe2c0617ee61062a3
@@ -204,9 +204,9 @@ F src/vdbe.c bddddefc5c7ec1c9cd3e4f9220eb813b43668605
 F src/vdbe.h d70a68bee196ab228914a3902c79dbd24342a0f2
 F src/vdbeInt.h 53a2f4696871712646c77351904576cca6ad9752
 F src/vdbeapi.c 950986b0f765b5b91aab1acb2b405d9450b749d1
-F src/vdbeaux.c 521187e184f642b3978c0ec00a0e165a45518ea6
+F src/vdbeaux.c d335ae5da63cd3b3a0f122e63d0e79e34a4e4fb1
 F src/vdbeblob.c e67757450ae8581a8b354d9d7e467e41502dfe38
-F src/vdbemem.c 53ab1c07800340d2ae100cb99537775a25b2efff
+F src/vdbemem.c 9798905787baae83d0b53b62030e32ecf7a0586f
 F src/vtab.c f1aba5a6dc1f83b97a39fbbc58ff8cbc76311347
 F src/walker.c 42bd3f00ca2ef5ae842304ec0d59903ef051412d
 F src/where.c 5a421d7265c79dc21c010e3218fd3abd448ec297
@@ -715,7 +715,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 11c77f4c2c2beee5267ea6e2f1a4bb845531b42c
-R 6fa763bbfd08cb93ca1062548d8a5a81
+P 81931259611ef10de731ea0e38cee92eb8629733
+R d1ec9689e8427e115f63f6ba1a6ce699
 U drh
-Z 3ec086d0c80add1adc32688c8dbd85a1
+Z d2872fc10d5a41a2536ecb51dcae9785
diff --git a/manifest.uuid b/manifest.uuid
index f4510cf544..5bde7c5ef5 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-81931259611ef10de731ea0e38cee92eb8629733
\ No newline at end of file
+208382e032134d9c78fe1cfcb98ce9defb4e3e26
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index b922b5f3cc..34b30a773c 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.589 2009/04/02 20:16:59 drh Exp $
+** $Id: btree.c,v 1.590 2009/04/05 12:22:09 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -5357,13 +5357,13 @@ static int balance_nonroot(BtCursor *pCur){
   }
   szCell = (u16*)&apCell[nMaxCells];
   aCopy[0] = (u8*)&szCell[nMaxCells];
-  assert( ((aCopy[0] - (u8*)0) & 7)==0 ); /* 8-byte alignment required */
+  assert( EIGHT_BYTE_ALIGNMENT(aCopy[0]) );
   for(i=1; i<NB; i++){
     aCopy[i] = &aCopy[i-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
     assert( ((aCopy[i] - (u8*)0) & 7)==0 ); /* 8-byte alignment required */
   }
   aSpace1 = &aCopy[NB-1][pBt->pageSize+ROUND8(sizeof(MemPage))];
-  assert( ((aSpace1 - (u8*)0) & 7)==0 ); /* 8-byte alignment required */
+  assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );
   if( ISAUTOVACUUM ){
     aFrom = &aSpace1[pBt->pageSize];
   }
diff --git a/src/memjournal.c b/src/memjournal.c
index 0261fefa2d..15665a0130 100644
--- a/src/memjournal.c
+++ b/src/memjournal.c
@@ -14,7 +14,7 @@
 ** The in-memory rollback journal is used to journal transactions for
 ** ":memory:" databases and when the journal_mode=MEMORY pragma is used.
 **
-** @(#) $Id: memjournal.c,v 1.10 2009/04/02 17:22:42 drh Exp $
+** @(#) $Id: memjournal.c,v 1.11 2009/04/05 12:22:09 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -237,6 +237,7 @@ static struct sqlite3_io_methods MemJournalMethods = {
 */
 void sqlite3MemJournalOpen(sqlite3_file *pJfd){
   MemJournal *p = (MemJournal *)pJfd;
+  assert( EIGHT_BYTE_ALIGNMENT(p) );
   memset(p, 0, sqlite3MemJournalSize());
   p->pMethod = &MemJournalMethods;
 }
diff --git a/src/pager.c b/src/pager.c
index f07c6270c5..928f05ec4a 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.577 2009/04/04 15:53:48 drh Exp $
+** @(#) $Id: pager.c,v 1.578 2009/04/05 12:22:09 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -3114,9 +3114,9 @@ int sqlite3PagerOpen(
   ** source file journal.c).
   */
   if( sqlite3JournalSize(pVfs)>sqlite3MemJournalSize() ){
-    journalFileSize = sqlite3JournalSize(pVfs);
+    journalFileSize = ROUND8(sqlite3JournalSize(pVfs));
   }else{
-    journalFileSize = sqlite3MemJournalSize();
+    journalFileSize = ROUND8(sqlite3MemJournalSize());
   }
 
   /* Set the output variable to NULL in case an error occurs. */
@@ -3172,23 +3172,25 @@ int sqlite3PagerOpen(
   **     Journal file name               (nPathname+8+1 bytes)
   */
   pPtr = (u8 *)sqlite3MallocZero(
-    sizeof(*pPager) +           /* Pager structure */
-    pcacheSize      +           /* PCache object */
-    pVfs->szOsFile  +           /* The main db file */
-    journalFileSize * 2 +       /* The two journal files */ 
-    nPathname + 1 +             /* zFilename */
-    nPathname + 8 + 1           /* zJournal */
+    ROUND8(sizeof(*pPager)) +      /* Pager structure */
+    ROUND8(pcacheSize) +           /* PCache object */
+    ROUND8(pVfs->szOsFile) +       /* The main db file */
+    journalFileSize * 2 +          /* The two journal files */ 
+    nPathname + 1 +                /* zFilename */
+    nPathname + 8 + 1              /* zJournal */
   );
+  assert( EIGHT_BYTE_ALIGNMENT(journalFileSize) );
   if( !pPtr ){
     sqlite3_free(zPathname);
     return SQLITE_NOMEM;
   }
   pPager =              (Pager*)(pPtr);
-  pPager->pPCache =    (PCache*)(pPtr += sizeof(*pPager));
-  pPager->fd =   (sqlite3_file*)(pPtr += pcacheSize);
-  pPager->sjfd = (sqlite3_file*)(pPtr += pVfs->szOsFile);
+  pPager->pPCache =    (PCache*)(pPtr += ROUND8(sizeof(*pPager)));
+  pPager->fd =   (sqlite3_file*)(pPtr += ROUND8(pcacheSize));
+  pPager->sjfd = (sqlite3_file*)(pPtr += ROUND8(pVfs->szOsFile));
   pPager->jfd =  (sqlite3_file*)(pPtr += journalFileSize);
   pPager->zFilename =    (char*)(pPtr += journalFileSize);
+  assert( EIGHT_BYTE_ALIGNMENT(pPager->jfd) );
 
   /* Fill in the Pager.zFilename and Pager.zJournal buffers, if required. */
   if( zPathname ){
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8fd2c89fe8..4eed2559f9 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.850 2009/04/01 18:03:01 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.851 2009/04/05 12:22:09 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -455,6 +455,11 @@ extern const int sqlite3one;
 */
 #define ROUNDDOWN8(x) ((x)&~7)
 
+/*
+** Assert that the pointer X is aligned to an 8-byte boundary.
+*/
+#define EIGHT_BYTE_ALIGNMENT(X)   ((((char*)(X) - (char*)0)&7)==0)
+
 /*
 ** An instance of the following structure is used to store the busy-handler
 ** callback for a given sqlite handle. 
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index c0e51adf9a..3f319da318 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -14,7 +14,7 @@
 ** to version 2.8.7, all this code was combined into the vdbe.c source file.
 ** But that file was getting too big so this subroutines were split out.
 **
-** $Id: vdbeaux.c,v 1.446 2009/03/25 15:43:09 danielk1977 Exp $
+** $Id: vdbeaux.c,v 1.447 2009/04/05 12:22:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
@@ -1023,6 +1023,7 @@ static void allocSpace(
   u8 *pEnd,            /* Pointer to 1 byte past the end of *ppFrom buffer */
   int *pnByte          /* If allocation cannot be made, increment *pnByte */
 ){
+  assert( EIGHT_BYTE_ALIGNMENT(*ppFrom) );
   if( (*(void**)pp)==0 ){
     nByte = ROUND8(nByte);
     if( (pEnd - *ppFrom)>=nByte ){
@@ -1096,6 +1097,8 @@ void sqlite3VdbeMakeReady(
     if( isExplain && nMem<10 ){
       nMem = 10;
     }
+    zCsr += (zCsr - (u8*)0)&7;
+    assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
 
     do {
       memset(zCsr, 0, zEnd-zCsr);
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 70feab9782..e5a8755a83 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -15,7 +15,7 @@
 ** only within the VDBE.  Interface routines refer to a Mem using the
 ** name sqlite_value
 **
-** $Id: vdbemem.c,v 1.139 2009/03/29 15:12:10 drh Exp $
+** $Id: vdbemem.c,v 1.140 2009/04/05 12:22:09 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
@@ -209,6 +209,7 @@ int sqlite3VdbeMemStringify(Mem *pMem, int enc){
   assert( !(fg&(MEM_Str|MEM_Blob)) );
   assert( fg&(MEM_Int|MEM_Real) );
   assert( (pMem->flags&MEM_RowSet)==0 );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
 
   if( sqlite3VdbeMemGrow(pMem, nByte, 0) ){
@@ -345,6 +346,7 @@ static i64 doubleToInt64(double r){
 i64 sqlite3VdbeIntValue(Mem *pMem){
   int flags;
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
   flags = pMem->flags;
   if( flags & MEM_Int ){
     return pMem->u.i;
@@ -373,6 +375,7 @@ i64 sqlite3VdbeIntValue(Mem *pMem){
 */
 double sqlite3VdbeRealValue(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
   if( pMem->flags & MEM_Real ){
     return pMem->r;
   }else if( pMem->flags & MEM_Int ){
@@ -403,6 +406,7 @@ void sqlite3VdbeIntegerAffinity(Mem *pMem){
   assert( pMem->flags & MEM_Real );
   assert( (pMem->flags & MEM_RowSet)==0 );
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
 
   pMem->u.i = doubleToInt64(pMem->r);
   if( pMem->r==(double)pMem->u.i ){
@@ -416,6 +420,8 @@ void sqlite3VdbeIntegerAffinity(Mem *pMem){
 int sqlite3VdbeMemIntegerify(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
   assert( (pMem->flags & MEM_RowSet)==0 );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
+
   pMem->u.i = sqlite3VdbeIntValue(pMem);
   MemSetTypeFlag(pMem, MEM_Int);
   return SQLITE_OK;
@@ -427,6 +433,8 @@ int sqlite3VdbeMemIntegerify(Mem *pMem){
 */
 int sqlite3VdbeMemRealify(Mem *pMem){
   assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
+  assert( EIGHT_BYTE_ALIGNMENT(pMem) );
+
   pMem->r = sqlite3VdbeRealValue(pMem);
   MemSetTypeFlag(pMem, MEM_Real);
   return SQLITE_OK;