diff --git a/manifest b/manifest
index 3c690bd921..28143ca21e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Version\s2.2.0\s(CVS\s453)
-D 2001-12-22T22:00:00
+C Comment\schanges.\s\sChange\sthe\suse\sof\sBTree\sso\sthat\seither\sthe\skey\sis\nan\sinteger\sor\sthe\sdata\sis\sempty.\s(CVS\s337)
+D 2001-12-31T02:48:51
 F Makefile.in 352fed589f09dd94347e0bb391d047118ebd6105
 F Makefile.template c88ffcb9c339e718f434d0c7f045bcd7eea125af
 F README a4c0ba11354ef6ba0776b400d057c59da47a4cc0
@@ -26,7 +26,7 @@ F src/delete.c f7690efc09ad6a2f1f3f0490e1b0cbb676bb95cf
 F src/expr.c ef1c365c5d558fa691878830501d3c36ed7edb25
 F src/hash.c 6f1a7712ae3aac8351662969aec5693740a2fbf7
 F src/hash.h a5f5b3ce2d086a172c5879b0b06a27a82eac9fac
-F src/insert.c 78c11efb6464ab01548f9b4c92b51cb30e3a7a3c
+F src/insert.c 74e249cf3c0e7da634eb115edeef77b42ec1d947
 F src/main.c 00a9f5603e130fc0b1a05f731731c9c99ebdc2dc
 F src/md5.c 52f677bfc590e09f71d07d7e327bd59da738d07c
 F src/os.c 07882cde5c61f26751b8ee76fd84726c1f7e453c
@@ -36,20 +36,20 @@ F src/pager.h f78d064c780855ff70beacbeba0e2324471b26fe
 F src/parse.y f050644e7a2586227686e8c1709aa2662b9bcf9c
 F src/printf.c 300a90554345751f26e1fc0c0333b90a66110a1d
 F src/random.c 2a9cc2c9716d14815fd4c2accf89d87a1143e46b
-F src/select.c bb7bf8d6e6154269145158952e041755cc4d9873
+F src/select.c 79120c805dc61513bc5902baa39991896718c5c4
 F src/shell.c 407095aaeeae78f42deb3e846b1ad77f8ed3b4ef
 F src/shell.tcl 27ecbd63dd88396ad16d81ab44f73e6c0ea9d20e
 F src/sqlite.h.in a4c11d38d62b1bfbd50a5804edee8ca54c1adc9b
-F src/sqliteInt.h 0b1e8ba2738440e2f06a4e01bb89230492bc203b
+F src/sqliteInt.h d2bfc012fb2c91652d67401e5d7a646a0c30a675
 F src/table.c c89698bd5bb4b8d14722d6ee7e9be014c383d24a
 F src/tclsqlite.c b82e4faeae89fdb7304b3c970979ade299336a1f
 F src/test1.c 41eabe255970ef947263b94145c9b2766bab8675
 F src/test2.c e9f99aa5ee73872819259d6612c11e55e1644321
 F src/test3.c d6775f95fd91f5b3cf0e2382a28e5aaeb68f745b
 F src/tokenize.c 830e9ef684334070a26583d94770bb869e2727bf
-F src/update.c 6a77d1459d2e829fd9dd244ce8b5ada7ac485317
+F src/update.c f9f48e78c13c79e32a55840414bea84479f9848d
 F src/util.c 8e9ca72d8288cae39c57c6f397abd14a56b14a38
-F src/vdbe.c f97e2d5bc6db936a2d001e0a1a94102e99ece821
+F src/vdbe.c b00fbd59e4a3264a2eec4dc7103c2cf52e9e49b0
 F src/vdbe.h e5cc6fb13d1905a4339db4d6dba4ab393c0765fa
 F src/where.c 178a908a40cc6d72150a747db69638a97bd86487
 F test/all.test 2a51e5395ac7c2c539689b123b9782a05e3837fe
@@ -119,7 +119,7 @@ F www/speed.tcl 83457b2bf6bb430900bd48ca3dd98264d9a916a5
 F www/sqlite.tcl 8b5884354cb615049aed83039f8dfe1552a44279
 F www/tclsqlite.tcl 880ef67cb4f2797b95bf1368fc4e0d8ca0fda956
 F www/vdbe.tcl 2013852c27a02a091d39a766bc87cff329f21218
-P a26d0880b20ca5534400a3689d1da31fe6aaa934
-R ca7de0eadaa033a7f4b8aa20c781d7ab
+P 6bb62d8fab621b79b2fd1601669b1d4c8a547774
+R c0cff954d526606a2c04afff4a5fc733
 U drh
-Z c050baa80c96802f9a0e4328455fadff
+Z 124639b155da23bf7001c10245c441bd
diff --git a/manifest.uuid b/manifest.uuid
index fda815e1f0..5a7e7ede15 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-6bb62d8fab621b79b2fd1601669b1d4c8a547774
\ No newline at end of file
+18e606f7486eb3a4ab128504d88a44f53d39e5b2
\ No newline at end of file
diff --git a/src/insert.c b/src/insert.c
index 425d8646b8..a3f41dc6fd 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle INSERT statements in SQLite.
 **
-** $Id: insert.c,v 1.29 2001/12/22 21:48:30 drh Exp $
+** $Id: insert.c,v 1.30 2001/12/31 02:48:51 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -132,6 +132,13 @@ void sqliteInsert(
   /* If the INSERT statement included an IDLIST term, then make sure
   ** all elements of the IDLIST really are columns of the table and 
   ** remember the column indices.
+  **
+  ** If the table has an INTEGER PRIMARY KEY column and that column
+  ** is named in the IDLIST, then record in the keyColumn variable
+  ** the index into IDLIST of the primary key column.  keyColumn is
+  ** the index of the primary key as it appears in IDLIST, not as
+  ** is appears in the original table.  (The index of the primary
+  ** key in the original table is pTab->iPKey.)
   */
   if( pColumn ){
     for(i=0; i<pColumn->nId; i++){
@@ -157,7 +164,8 @@ void sqliteInsert(
   }
 
   /* If there is not IDLIST term but the table has an integer primary
-  ** key, the set the keyColumn variable to the primary key column.
+  ** key, the set the keyColumn variable to the primary key column index
+  ** in the original table definition.
   */
   if( pColumn==0 ){
     keyColumn = pTab->iPKey;
@@ -205,7 +213,7 @@ void sqliteInsert(
     sqliteVdbeAddOp(v, OP_NewRecno, base, 0);
   }
 
-  /* If there are indices, we'll need this record number again, so make
+  /* If there are indices, we'll need the new record number again, so make
   ** a copy.
   */
   if( pTab->pIndex ){
@@ -219,7 +227,7 @@ void sqliteInsert(
     if( i==pTab->iPKey ){
       /* The value of the INTEGER PRIMARY KEY column is always a NULL.
       ** Whenever this column is used, the record number will be substituted
-      ** in its place, so there is no point it it taking up space in
+      ** in its place, so there is no point in it taking up space in
       ** the data record. */
       sqliteVdbeAddOp(v, OP_String, 0, 0);
       continue;
diff --git a/src/select.c b/src/select.c
index cc6e174bf6..399c56389a 100644
--- a/src/select.c
+++ b/src/select.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle SELECT statements in SQLite.
 **
-** $Id: select.c,v 1.51 2001/12/22 14:49:25 drh Exp $
+** $Id: select.c,v 1.52 2001/12/31 02:48:51 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -130,7 +130,6 @@ static int selectInnerLoop(
     sqliteVdbeAddOp(v, OP_Goto, 0, iContinue);
     sqliteVdbeResolveLabel(v, lbl);
     sqliteVdbeAddOp(v, OP_String, 0, 0);
-    sqliteVdbeChangeP3(v, -1, "", P3_STATIC);
     sqliteVdbeAddOp(v, OP_Put, distinct, 0);
   }
 
@@ -159,7 +158,6 @@ static int selectInnerLoop(
   if( eDest==SRT_Union ){
     sqliteVdbeAddOp(v, OP_MakeRecord, nColumn, 0);
     sqliteVdbeAddOp(v, OP_String, iParm, 0);
-    sqliteVdbeChangeP3(v, -1, "", P3_STATIC);
     sqliteVdbeAddOp(v, OP_Put, iParm, 0);
   }else 
 
@@ -189,7 +187,6 @@ static int selectInnerLoop(
   if( eDest==SRT_Set ){
     assert( nColumn==1 );
     sqliteVdbeAddOp(v, OP_String, 0, 0);
-    sqliteVdbeChangeP3(v, -1, "", P3_STATIC);
     sqliteVdbeAddOp(v, OP_Put, iParm, 0);
   }else 
 
@@ -909,7 +906,6 @@ int sqliteSelect(
     sqliteVdbeAddOp(v, OP_AggReset, 0, pParse->nAgg);
     if( pGroupBy==0 ){
       sqliteVdbeAddOp(v, OP_String, 0, 0);
-      sqliteVdbeChangeP3(v, -1, "", P3_STATIC);
       sqliteVdbeAddOp(v, OP_AggFocus, 0, 0);
       for(i=0; i<pParse->nAgg; i++){
         Expr *pE;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index ef7021bd43..ead834aa69 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.73 2001/12/21 14:30:43 drh Exp $
+** @(#) $Id: sqliteInt.h,v 1.74 2001/12/31 02:48:51 drh Exp $
 */
 #include "sqlite.h"
 #include "hash.h"
@@ -230,7 +230,7 @@ struct Table {
   char *zName;     /* Name of the table */
   int nCol;        /* Number of columns in this table */
   Column *aCol;    /* Information about each column */
-  int iPKey;       /* Use this column as the record-number for each row */
+  int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
   Index *pIndex;   /* List of SQL indexes on this table. */
   int tnum;        /* Page containing root for this table */
   u8 readOnly;     /* True if this table should not be written by the user */
diff --git a/src/update.c b/src/update.c
index 7ea634e6c8..0bac200e26 100644
--- a/src/update.c
+++ b/src/update.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle UPDATE statements.
 **
-** $Id: update.c,v 1.24 2001/12/22 14:49:25 drh Exp $
+** $Id: update.c,v 1.25 2001/12/31 02:48:51 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -49,7 +49,7 @@ void sqliteUpdate(
   /* Locate the table which we want to update.  This table has to be
   ** put in an IdList structure because some of the subroutines we
   ** will be calling are designed to work with multiple tables and expect
-  ** an IdList* parameter instead of just a Table* parameger.
+  ** an IdList* parameter instead of just a Table* parameter.
   */
   pTabList = sqliteIdListAppend(0, pTableName);
   if( pTabList==0 ) goto update_cleanup;
@@ -119,7 +119,8 @@ void sqliteUpdate(
 
   /* Allocate memory for the array apIdx[] and fill it with pointers to every
   ** index that needs to be updated.  Indices only need updating if their
-  ** key includes one of the columns named in pChanges.
+  ** key includes one of the columns named in pChanges or if the record
+  ** number of the original table entry is changing.
   */
   for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
     if( chngRecno ){
@@ -203,7 +204,12 @@ void sqliteUpdate(
     sqliteVdbeAddOp(v, OP_Dup, 0, 0);
     pIdx = apIdx[i];
     for(j=0; j<pIdx->nColumn; j++){
-      sqliteVdbeAddOp(v, OP_Column, base, pIdx->aiColumn[j]);
+      int x = pIdx->aiColumn[j];
+      if( x==pTab->iPKey ){
+        sqliteVdbeAddOp(v, OP_Dup, j, 0);
+      }else{
+        sqliteVdbeAddOp(v, OP_Column, base, x);
+      }
     }
     sqliteVdbeAddOp(v, OP_MakeIdxKey, pIdx->nColumn, 0);
     sqliteVdbeAddOp(v, OP_IdxDelete, base+i+1, 0);
@@ -233,7 +239,7 @@ void sqliteUpdate(
     }
   }
 
-  /* If changing the record number, delete the hold record.
+  /* If changing the record number, delete the old record.
   */
   if( chngRecno ){
     sqliteVdbeAddOp(v, OP_Delete, 0, 0);
diff --git a/src/vdbe.c b/src/vdbe.c
index c8c237609c..7079e179e1 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -30,7 +30,7 @@
 ** But other routines are also provided to help in building up
 ** a program instruction by instruction.
 **
-** $Id: vdbe.c,v 1.102 2001/12/22 14:49:25 drh Exp $
+** $Id: vdbe.c,v 1.103 2001/12/31 02:48:51 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -56,11 +56,11 @@ typedef struct VdbeOp Op;
 typedef unsigned char Bool;
 
 /*
-** A cursor is a pointer into a database file.  The database file
-** can represent either an SQL table or an SQL index.  Each file is
-** a bag of key/data pairs.  The cursor can loop over all key/data
-** pairs (in an arbitrary order) or it can retrieve a particular
-** key/data pair given a copy of the key.
+** A cursor is a pointer into a single BTree within a database file.
+** The cursor can seek to a BTree entry with a particular key, or
+** loop over all entries of the Btree.  You can also insert new BTree
+** entries or retrieve the key or data from the entry that the cursor
+** is currently pointing to.
 ** 
 ** Every cursor that the virtual machine has open is represented by an
 ** instance of the following structure.
@@ -98,7 +98,7 @@ struct Sorter {
 ** layer without having to malloc.  NBFS is short for Number of Bytes
 ** For Strings.
 */
-#define NBFS 30
+#define NBFS 32
 
 /*
 ** A single level of the stack is an instance of the following
@@ -170,8 +170,8 @@ struct Set {
 
 /*
 ** A Keylist is a bunch of keys into a table.  The keylist can
-** grow without bound.  The keylist stores the keys of database
-** records that need to be deleted.
+** grow without bound.  The keylist stores the ROWIDs of database
+** records that need to be deleted or updated.
 */
 typedef struct Keylist Keylist;
 struct Keylist {
@@ -394,7 +394,7 @@ void sqliteVdbeChangeP1(Vdbe *p, int addr, int val){
 ** first null byte.  If n>0 then copy n+1 bytes of zP3.
 **
 ** If n==P3_STATIC  it means that zP3 is a pointer to a constant static
-** string we can just copy the pointer.  n==P3_POINTER means zP3 is
+** string and we can just copy the pointer.  n==P3_POINTER means zP3 is
 ** a pointer to some object other than a string.
 **
 ** If addr<0 then change P3 on the most recently inserted instruction.
@@ -1177,6 +1177,7 @@ case OP_String: {
   z = pOp->p3;
   if( z==0 ){
     zStack[i] = 0;
+    aStack[i].n = 0;
     aStack[i].flags = STK_Null;
   }else{
     zStack[i] = z;