From 7cf6e4de35ce301cb9c68fe51314c4cd9469b8aa Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 19 May 2004 14:56:55 +0000
Subject: [PATCH] Change opcode names and comments to better describe the
 operation of the incrKey flag.  OP_MoveTo becomes OP_MoveGe. (CVS 1407)

FossilOrigin-Name: 8f249c45cbc77f4320798ff1a830b55e5c74888a
---
 manifest        |  28 +++++------
 manifest.uuid   |   2 +-
 src/delete.c    |   8 +---
 src/insert.c    |  11 ++---
 src/select.c    |   4 +-
 src/update.c    |   7 +--
 src/vdbe.c      | 121 ++++++++++++++++++++++++++----------------------
 src/vdbeInt.h   |   2 +-
 src/vdbeaux.c   |  15 ++++--
 src/where.c     |  45 +++++++-----------
 test/where.test |   3 +-
 11 files changed, 121 insertions(+), 125 deletions(-)

diff --git a/manifest b/manifest
index 2371a2cc16..8c1cda16d3 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Bug\sfixes\sin\swhere.c.\s\sThe\swhere.test\stest\sworks\sagain.\s(CVS\s1406)
-D 2004-05-19T13:13:08
+C Change\sopcode\snames\sand\scomments\sto\sbetter\sdescribe\sthe\soperation\sof\nthe\sincrKey\sflag.\s\sOP_MoveTo\sbecomes\sOP_MoveGe.\s(CVS\s1407)
+D 2004-05-19T14:56:56
 F Makefile.in ab7b0d5118e2da97bac66be8684a1034e3500f5a
 F Makefile.linux-gcc b86a99c493a5bfb402d1d9178dcdc4bd4b32f906
 F README f1de682fbbd94899d50aca13d387d1b3fd3be2dd
@@ -29,13 +29,13 @@ F src/btree_rb.c 9d7973e266ee6f9c61ce592f68742ce9cd5b10e5
 F src/build.c 84a9b37700a18db370b9dbb77f1636df5cdf0290
 F src/copy.c 4d2038602fd0549d80c59bda27d96f13ea9b5e29
 F src/date.c 0eb0a89960bb45c7f7e768748605a7a97b0c8064
-F src/delete.c a069dcc2ec0cc3487c8ababebc59a429b4556144
+F src/delete.c 2e1dda38345416a1ea1c0a6468589a7472334dac
 F src/encode.c a876af473d1d636faa3dca51c7571f2e007eea37
 F src/expr.c de3d86e98d9073399a8173610fb9f02d0e197aea
 F src/func.c cfbb7096efb58e2857e3b312a8958a12774b625a
 F src/hash.c 440c2f8cb373ee1b4e13a0988489c7cd95d55b6f
 F src/hash.h 762d95f1e567664d1eafc1687de755626be962fb
-F src/insert.c 60cc57b8468749d7e023798b9d7f91eeb4cd279a
+F src/insert.c 0ee4c4039fede2b9ab594c4d2db24c9b22e0fbc5
 F src/main.c 4b82d7e78f4c9799343b02740a5ba9768d5e464d
 F src/md5.c 8e39fdae6d8776b87558e91dcc94740c9b635a9c
 F src/os.c ddcda92f7fd71b4513c57c1ec797917f206d504e
@@ -46,7 +46,7 @@ F src/parse.y d2e226650738931c047c2562326ed05882af2330
 F src/pragma.c 2332e7fa9d7cd4b21f30583a696bee36628404ca
 F src/printf.c ef750e8e2398ca7e8b58be991075f08c6a7f0e53
 F src/random.c eff68e3f257e05e81eae6c4d50a51eb88beb4ff3
-F src/select.c 2981cafe3b21ca06c97ddec8c7181f209a06ee82
+F src/select.c d01c03462d57b9d1ea25eea297bbd2c1b1c70e47
 F src/shell.c 0c4662e13bfbfd3d13b066c5859cc97ad2f95d21
 F src/sqlite.h.in 8c62076ea226b1870df977d7438bf99383d02387
 F src/sqliteInt.h 1da4a9c26da43f235c45c1de0c49fadf6c40d0e6
@@ -59,15 +59,15 @@ F src/test4.c b3fab9aea7a8940a8a7386ce1c7e2157b09bd296
 F src/test5.c c92dca7028b19b9c8319d55e0a5037fc183640a6
 F src/tokenize.c e7536dd31205d5afb76c1bdc832dea009c7a3847
 F src/trigger.c 11afe9abfba13a2ba142944c797c952e162d117f
-F src/update.c 0cc7291dd0e0f82cf93085e49c973e8ef9e51fd5
+F src/update.c 1f6687f8d1085f896a24c0fa13d802223ed55539
 F src/utf.c 48c537bf7990ce32a36b051401874d024ec2a07b
 F src/util.c b72f775a6c3fa404d70250382f63d708e17bc332
 F src/vacuum.c c134702e023db8778e6be59ac0ea7b02315b5476
-F src/vdbe.c b64632880456575000b369f11ffe118965184dce
+F src/vdbe.c 42ecfcd3bf67b9922702cbad2dd87be0bc1cc986
 F src/vdbe.h 314e9c07db73a42a6ba91ab7539e27652fc88870
-F src/vdbeInt.h 3f76e27be527f4848dc2aae898f2d8709eb1b32c
-F src/vdbeaux.c 5743e15988d1cbe2db055c1cb6faaa062c1ec601
-F src/where.c 67bbdef0ce7fcd661cbf02f3fd91ff8cdb7a4a44
+F src/vdbeInt.h faaa64433d2498f7a6eabccebac854e097b83680
+F src/vdbeaux.c 453e9f6d98fffec8c07ecd99ad9e1bc5b5cf09b1
+F src/where.c e7a7eeb46a81f8ccf84a297db99b3121429769cb
 F test/all.test 569a92a8ee88f5300c057cc4a8f50fbbc69a3242
 F test/attach.test cb9b884344e6cfa5e165965d5b1adea679a24c83
 F test/attach2.test 7c388dee63a4c1997695c3d41957f32ce784ac56
@@ -152,7 +152,7 @@ F test/vacuum.test a2a44544df719666efb51afbfeb6062fd59a672a
 F test/varint.test ab7b110089a08b9926ed7390e7e97bdefeb74102
 F test/version.test 2ba212ba06380e65e476bdf2fcd390e8b05af5a0
 F test/view.test 1ee12c6f8f4791a2c0655120d5562a49400cfe53
-F test/where.test 45a816fc3b055a8306a1482f98b7c0b2cf14581b
+F test/where.test 32135ef3fe2bd427a94ad4982c35565c46abafe2
 F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
 F tool/lemon.c f4fb7226c930435e994441a470ed60a7c540f518
 F tool/lempar.c 0b5e7a58634e0d448929b8e85f7981c2aa708d57
@@ -193,7 +193,7 @@ F www/sqlite.tcl 3c83b08cf9f18aa2d69453ff441a36c40e431604
 F www/tclsqlite.tcl b9271d44dcf147a93c98f8ecf28c927307abd6da
 F www/vdbe.tcl 9b9095d4495f37697fd1935d10e14c6015e80aa1
 F www/whentouse.tcl a8335bce47cc2fddb07f19052cb0cb4d9129a8e4
-P 821b0b297c11a5e8d08d73b5eff810652e5a0d27
-R c82e653b769eb6c799477d31b330ecb3
+P 7c31e257e2d109bfedf63dc307b422e1abd46d0e
+R 5feb1ed8cc5ac536a6c28ba5fb650adc
 U drh
-Z 82230e305545f87ef38ec9ab9f82ee14
+Z 09dcaf5d692d1cd749b1f77eda04144f
diff --git a/manifest.uuid b/manifest.uuid
index d826b0d5d1..7b56c40d86 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7c31e257e2d109bfedf63dc307b422e1abd46d0e
\ No newline at end of file
+8f249c45cbc77f4320798ff1a830b55e5c74888a
\ No newline at end of file
diff --git a/src/delete.c b/src/delete.c
index df1a0485d5..939519a09b 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -12,7 +12,7 @@
 ** This file contains C code routines that are called by the parser
 ** to handle DELETE FROM statements.
 **
-** $Id: delete.c,v 1.67 2004/05/18 09:58:07 danielk1977 Exp $
+** $Id: delete.c,v 1.68 2004/05/19 14:56:56 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -234,8 +234,7 @@ void sqlite3DeleteFrom(
         sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
         sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
       }
-      sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
-
+      sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
       sqlite3VdbeAddOp(v, OP_Recno, iCur, 0);
       sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
       sqlite3VdbeAddOp(v, OP_PutIntKey, oldIdx, 0);
@@ -394,6 +393,3 @@ void sqlite3GenerateRowIndexDelete(
     sqlite3VdbeAddOp(v, OP_IdxDelete, iCur+i, 0);
   }
 }
-
-
-
diff --git a/src/insert.c b/src/insert.c
index 12ed4a4d53..52096a8e5e 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 1.102 2004/05/18 09:58:07 danielk1977 Exp $
+** $Id: insert.c,v 1.103 2004/05/19 14:56:56 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -823,7 +823,7 @@ void sqlite3GenerateConstraintChecks(
         sqlite3GenerateRowIndexDelete(pParse->db, v, pTab, base, 0);
         if( isUpdate ){
           sqlite3VdbeAddOp(v, OP_Dup, nCol+hasTwoRecnos, 1);
-          sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
+          sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
         }
         seenReplace = 1;
         break;
@@ -840,7 +840,7 @@ void sqlite3GenerateConstraintChecks(
     if( isUpdate ){
       sqlite3VdbeChangeP2(v, jumpInst1, contAddr);
       sqlite3VdbeAddOp(v, OP_Dup, nCol+1, 1);
-      sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
+      sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
     }
   }
 
@@ -926,7 +926,7 @@ void sqlite3GenerateConstraintChecks(
         sqlite3GenerateRowDelete(pParse->db, v, pTab, base, 0);
         if( isUpdate ){
           sqlite3VdbeAddOp(v, OP_Dup, nCol+extra+1+hasTwoRecnos, 1);
-          sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
+          sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
         }
         seenReplace = 1;
         break;
@@ -1010,6 +1010,3 @@ int sqlite3OpenTableAndIndices(Parse *pParse, Table *pTab, int base){
   }
   return i;
 }
-
-
-
diff --git a/src/select.c b/src/select.c
index 1e1ab300cd..5f49313ed7 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 1.168 2004/05/18 22:38:32 drh Exp $
+** $Id: select.c,v 1.169 2004/05/19 14:56:56 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -2023,7 +2023,7 @@ static int simpleMinMaxQuery(Parse *pParse, Select *p, int eDest, int iParm){
     sqlite3VdbeAddOp(v, seekOp, base+1, 0);
     sqlite3VdbeAddOp(v, OP_IdxRecno, base+1, 0);
     sqlite3VdbeAddOp(v, OP_Close, base+1, 0);
-    sqlite3VdbeAddOp(v, OP_MoveTo, base, 0);
+    sqlite3VdbeAddOp(v, OP_MoveGe, base, 0);
   }
   eList.nExpr = 1;
   memset(&eListItem, 0, sizeof(eListItem));
diff --git a/src/update.c b/src/update.c
index 71c6c6f840..e35ee4c87d 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 1.76 2004/05/18 09:58:08 danielk1977 Exp $
+** $Id: update.c,v 1.77 2004/05/19 14:56:57 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -262,7 +262,7 @@ void sqlite3Update(
       sqlite3VdbeAddOp(v, OP_OpenRead, iCur, pTab->tnum);
       sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
     }
-    sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
+    sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
 
     /* Generate the OLD table
     */
@@ -458,6 +458,3 @@ update_cleanup:
   sqlite3ExprDelete(pWhere);
   return;
 }
-
-
-
diff --git a/src/vdbe.c b/src/vdbe.c
index ac28e3b2a6..688670553e 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.303 2004/05/19 13:13:08 drh Exp $
+** $Id: vdbe.c,v 1.304 2004/05/19 14:56:57 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -52,7 +52,7 @@
 
 /*
 ** The following global variable is incremented every time a cursor
-** moves, either by the OP_MoveTo or the OP_Next opcode.  The test
+** moves, either by the OP_MoveXX, OP_Next, or OP_Prev opcodes.  The test
 ** procedures use this information to make sure that indices are
 ** working correctly.  This variable has no function other than to
 ** help verify the correct operation of the library.
@@ -2757,43 +2757,50 @@ case OP_Close: {
   break;
 }
 
-/* Opcode: MoveTo P1 P2 *
+/* Opcode: MoveGe P1 P2 *
 **
 ** Pop the top of the stack and use its value as a key.  Reposition
-** cursor P1 so that it points to an entry with a matching key.  If
-** the table contains no record with a matching key, then the cursor
-** is left pointing at the first record that is greater than the key.
+** cursor P1 so that it points to the smallest entry that is greater
+** than or equal to the key that was popped ffrom the stack.
+** If there are no records greater than or equal to the key and P2 
+** is not zero, then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveLt, MoveGt, MoveLe
+*/
+/* Opcode: MoveGt P1 P2 *
+**
+** Pop the top of the stack and use its value as a key.  Reposition
+** cursor P1 so that it points to the smallest entry that is greater
+** than the key from the stack.
 ** If there are no records greater than the key and P2 is not zero,
-** then an immediate jump to P2 is made.
+** then jump to P2.
 **
-** If P3 is the "+" string (or any other non-NULL string) then the
-** index taken from the top of the stack is temporarily increased by
-** an epsilon prior to the move.  This causes the P1 cursor to move
-** to the first entry which is greater than the index on the top of
-** the stack rather than the first entry that is equal to the top of
-** the stack.
-**
-** See also: Found, NotFound, Distinct, MoveLt
+** See also: Found, NotFound, Distinct, MoveLt, MoveGe, MoveLe
 */
 /* Opcode: MoveLt P1 P2 *
 **
 ** Pop the top of the stack and use its value as a key.  Reposition
-** cursor P1 so that it points to the entry with the largest key that is
-** less than the key popped from the stack.
-** If there are no records less than than the key and P2
-** is not zero then an immediate jump to P2 is made.
+** cursor P1 so that it points to the largest entry that is less
+** than the key from the stack.
+** If there are no records less than the key and P2 is not zero,
+** then jump to P2.
 **
-** If P3 is the "+" string (or any other non-NULL string) then the
-** index taken from the top of the stack is temporarily increased by
-** an epsilon prior to the move.  This causes the P1 cursor to move
-** to the smallest entry that is greater than or equal to the top of
-** the stack rather than the largest entry that is less than the top
-** of the stack.
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLe
+*/
+/* Opcode: MoveLe P1 P2 *
 **
-** See also: MoveTo
+** Pop the top of the stack and use its value as a key.  Reposition
+** cursor P1 so that it points to the largest entry that is less than
+** or equal to the key that was popped from the stack.
+** If there are no records less than or eqal to the key and P2 is not zero,
+** then jump to P2.
+**
+** See also: Found, NotFound, Distinct, MoveGt, MoveGe, MoveLt
 */
 case OP_MoveLt:
-case OP_MoveTo: {
+case OP_MoveLe:
+case OP_MoveGe:
+case OP_MoveGt: {
   int i = pOp->p1;
   Cursor *pC;
 
@@ -2802,13 +2809,15 @@ case OP_MoveTo: {
   pC = p->apCsr[i];
   if( pC->pCursor!=0 ){
     int res, oc;
+    oc = pOp->opcode;
     pC->nullRow = 0;
+    pC->incrKey = oc==OP_MoveGt || oc==OP_MoveLe;
     if( pC->intKey ){
       i64 iKey;
       assert( !pOp->p3 );
       Integerify(pTos);
       iKey = intToKey(pTos->i);
-      if( pOp->p2==0 && pOp->opcode==OP_MoveTo ){
+      if( pOp->p2==0 && pOp->opcode==OP_MoveGe ){
         pC->movetoTarget = iKey;
         pC->deferredMoveto = 1;
         Release(pTos);
@@ -2831,14 +2840,16 @@ case OP_MoveTo: {
     pC->cacheValid = 0;
     pC->incrKey = 0;
     sqlite3_search_count++;
-    oc = pOp->opcode;
-    if( oc==OP_MoveTo && res<0 ){
-      sqlite3BtreeNext(pC->pCursor, &res);
-      pC->recnoIsValid = 0;
-      if( res && pOp->p2>0 ){
-        pc = pOp->p2 - 1;
+    if( oc==OP_MoveGe || oc==OP_MoveGt ){
+      if( res<0 ){
+        sqlite3BtreeNext(pC->pCursor, &res);
+        pC->recnoIsValid = 0;
+        if( res && pOp->p2>0 ){
+          pc = pOp->p2 - 1;
+        }
       }
-    }else if( oc==OP_MoveLt ){
+    }else{
+      assert( oc==OP_MoveLt || oc==OP_MoveLe );
       if( res>=0 ){
         sqlite3BtreePrevious(pC->pCursor, &res);
         pC->recnoIsValid = 0;
@@ -2927,12 +2938,13 @@ case OP_Found: {
 ** using MakeIdxKey.  Call it K.  This instruction pops R from the
 ** stack but it leaves K unchanged.
 **
-** P1 is an index.  So all but the last four bytes of K are an
-** index string.  The last four bytes of K are a record number.
+** P1 is an index.  So it has no data and its key consists of a
+** record generated by OP_MakeIdxKey.  This key contains one or more
+** fields followed by a varint ROWID.
 **
 ** This instruction asks if there is an entry in P1 where the
-** index string matches K but the record number is different
-** from R.  If there is no such entry, then there is an immediate
+** fields matches K but the rowid is different from R.
+** If there is no such entry, then there is an immediate
 ** jump to P2.  If any entry does exist where the index string
 ** matches K but the record number is not R, then the record
 ** number for that entry is pushed onto the stack and control
@@ -2987,7 +2999,7 @@ case OP_IsUnique: {
         break;
       }
     }
-    rc = sqlite3VdbeIdxKeyCompare(pCx, len, zKey, 0, &res); 
+    rc = sqlite3VdbeIdxKeyCompare(pCx, len, zKey, &res); 
     if( rc!=SQLITE_OK ) goto abort_due_to_error;
     if( res>0 ){
       pc = pOp->p2 - 1;
@@ -3685,7 +3697,7 @@ case OP_IdxPut: {
         int c;
         sqlite3BtreeKeySize(pCrsr, &n);
         if( n==nKey && 
-            sqlite3VdbeIdxKeyCompare(pC, len, zKey, 0, &c)==SQLITE_OK
+            sqlite3VdbeIdxKeyCompare(pC, len, zKey, &c)==SQLITE_OK
             && c==0
         ){
           rc = SQLITE_CONSTRAINT;
@@ -3802,32 +3814,31 @@ case OP_IdxRecno: {
   break;
 }
 
-/* Opcode: IdxGT P1 P2 P3
+/* Opcode: IdxGT P1 P2 *
 **
 ** Compare the top of the stack against the key on the index entry that
 ** cursor P1 is currently pointing to.  Ignore the ROWID of the
 ** index entry.  If the index entry is greater than the top of the stack
 ** then jump to P2.  Otherwise fall through to the next instruction.
 ** In either case, the stack is popped once.
-**
-** If P3 is the "+" string (or any other non-NULL string) then the
-** index taken from the top of the stack is temporarily increased by
-** an epsilon prior to the comparison.
 */
-/* Opcode: IdxGE P1 P2 *
+/* Opcode: IdxGE P1 P2 P3
 **
 ** Compare the top of the stack against the key on the index entry that
 ** cursor P1 is currently pointing to.  Ignore the ROWID of the
-** index entry.  If the index entry is greater than or equal to 
+** index entry.  If the index in the cursor is greater than or equal to 
 ** the top of the stack
 ** then jump to P2.  Otherwise fall through to the next instruction.
 ** In either case, the stack is popped once.
 **
 ** If P3 is the "+" string (or any other non-NULL string) then the
 ** index taken from the top of the stack is temporarily increased by
-** an epsilon prior to the comparison.
+** an epsilon prior to the comparison.  This make the opcode work
+** like IdxGT except that if the key from the stack is a prefix of
+** the key in the cursor, the result is false whereas it would be
+** true with IdxGT.
 */
-/* Opcode: IdxLT P1 P2 *
+/* Opcode: IdxLT P1 P2 P3
 **
 ** Compare the top of the stack against the key on the index entry that
 ** cursor P1 is currently pointing to.  Ignore the ROWID of the
@@ -3837,7 +3848,8 @@ case OP_IdxRecno: {
 **
 ** If P3 is the "+" string (or any other non-NULL string) then the
 ** index taken from the top of the stack is temporarily increased by
-** an epsilon prior to the comparison.
+** an epsilon prior to the comparison.  This makes the opcode work
+** like IdxLE.
 */
 case OP_IdxLT:
 case OP_IdxGT:
@@ -3853,10 +3865,9 @@ case OP_IdxGE: {
  
     Stringify(pTos);
     assert( pC->deferredMoveto==0 );
-    if( pOp->p3 ){
-      pC->incrKey = 1;
-    }
-    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, pTos->z, 0, &res);
+    pC->incrKey = pOp->p3!=0;
+    assert( pOp->p3==0 || pOp->opcode!=OP_IdxGT );
+    rc = sqlite3VdbeIdxKeyCompare(pC, pTos->n, pTos->z, &res);
     pC->incrKey = 0;
     if( rc!=SQLITE_OK ){
       break;
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 6d99459bbe..f86a4aff31 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -328,7 +328,7 @@ int sqlite3VdbeSerialPut(unsigned char *, const Mem *);
 int sqlite3VdbeSerialGet(const unsigned char *, u64, Mem *);
 
 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
-int sqlite3VdbeIdxKeyCompare(Cursor*, int , const unsigned char*, int, int*);
+int sqlite3VdbeIdxKeyCompare(Cursor*, int , const unsigned char*, int*);
 int sqlite3VdbeIdxRowid(BtCursor *, i64 *);
 int sqlite3MemCompare(Mem *, Mem *);
 int sqlite3VdbeKeyCompare(void*,int,const void*,int, const void*);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 579c80d3a5..9c4f702355 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1626,11 +1626,16 @@ int sqlite3VdbeIdxRowid(BtCursor *pCur, i64 *rowid){
   return SQLITE_OK;
 }
 
+/*
+** Compare the key of index entry that cursor pC is point to against
+** the key string in pKey (of length nKey).  Write into *pRes a number
+** that is negative, zero, or positive if pC is less than, equal to,
+** or greater than pKey.  Return SQLITE_OK on success.
+*/
 int sqlite3VdbeIdxKeyCompare(
-  Cursor *pC, 
-  int nKey, const unsigned char *pKey,
-  int ignorerowid,
-  int *res
+  Cursor *pC,                 /* The cursor to compare against */
+  int nKey, const u8 *pKey,   /* The key to compare */
+  int *res                    /* Write the comparison result here */
 ){
   unsigned char *pCellKey;
   u64 nCellKey;
@@ -1662,10 +1667,12 @@ int sqlite3VdbeIdxKeyCompare(
   len = nCellKey-2;
   while( pCellKey[len] && --len );
 
+#if 0
   if( ignorerowid ){
     nKey--;
     while( pKey[nKey] && --nKey );
   }
+#endif
   *res = sqlite3VdbeKeyCompare(pC, len, pCellKey, nKey, pKey);
   
   if( freeCellKey ){
diff --git a/src/where.c b/src/where.c
index cc50d1a58e..cc8ac97dde 100644
--- a/src/where.c
+++ b/src/where.c
@@ -12,7 +12,7 @@
 ** This module contains C code that generates VDBE code used to process
 ** the WHERE clause of SQL statements.
 **
-** $Id: where.c,v 1.97 2004/05/19 13:13:08 drh Exp $
+** $Id: where.c,v 1.98 2004/05/19 14:56:57 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -809,15 +809,6 @@ WhereInfo *sqlite3WhereBegin(
       sqlite3IndexAffinityStr(v, pIdx);
       sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 0);
 
-      /* Choose a testOp that will determine when we have moved past the
-      ** last element of the table that matches the index key we just
-      ** created */
-      if( nColumn==pIdx->nColumn || pLevel->bRev ){
-        testOp = OP_IdxGT;
-      }else{
-        testOp = OP_IdxGE;
-      }
-
       /* Generate code (1) to move to the first matching element of the table.
       ** Then generate code (2) that jumps to "brk" after the cursor is past
       ** the last matching element of the table.  The code (1) is executed
@@ -825,18 +816,18 @@ WhereInfo *sqlite3WhereBegin(
       ** iteration of the scan to see if the scan has finished. */
       if( pLevel->bRev ){
         /* Scan in reverse order */
-        sqlite3VdbeAddOp(v, OP_MoveLt, pLevel->iCur, brk);
-        sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
+        sqlite3VdbeAddOp(v, OP_MoveLe, pLevel->iCur, brk);
         start = sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
         sqlite3VdbeAddOp(v, OP_IdxLT, pLevel->iCur, brk);
         pLevel->op = OP_Prev;
       }else{
         /* Scan in the forward order */
-        sqlite3VdbeAddOp(v, OP_MoveTo, pLevel->iCur, brk);
+        sqlite3VdbeAddOp(v, OP_MoveGe, pLevel->iCur, brk);
         start = sqlite3VdbeAddOp(v, OP_MemLoad, pLevel->iMem, 0);
-        sqlite3VdbeAddOp(v, testOp, pLevel->iCur, brk);
-        if( testOp==OP_IdxGE ){
-          sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
+        if( nColumn==pIdx->nColumn || 0 ){
+          sqlite3VdbeAddOp(v, OP_IdxGT, pLevel->iCur, brk);
+        }else{
+          sqlite3VdbeOp3(v, OP_IdxGE, pLevel->iCur, brk, "+", P3_STATIC);
         }
         pLevel->op = OP_Next;
       }
@@ -846,7 +837,7 @@ WhereInfo *sqlite3WhereBegin(
       if( i==pTabList->nSrc-1 && pushKey ){
         haveKey = 1;
       }else{
-        sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
+        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
         haveKey = 0;
       }
       pLevel->p1 = pLevel->iCur;
@@ -871,7 +862,7 @@ WhereInfo *sqlite3WhereBegin(
         }
         sqlite3VdbeAddOp(v, OP_ForceInt,
           aExpr[k].p->op==TK_LT || aExpr[k].p->op==TK_GT, brk);
-        sqlite3VdbeAddOp(v, OP_MoveTo, iCur, brk);
+        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, brk);
         aExpr[k].p = 0;
       }else{
         sqlite3VdbeAddOp(v, OP_Rewind, iCur, brk);
@@ -1023,10 +1014,8 @@ WhereInfo *sqlite3WhereBegin(
         sqlite3VdbeAddOp(v, OP_MakeKey, nCol, 0);
         sqlite3IndexAffinityStr(v, pIdx);
         if( pLevel->bRev ){
-          sqlite3VdbeAddOp(v, OP_MoveLt, pLevel->iCur, brk);
-          if( leFlag ){
-            sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
-          }
+          int op = leFlag ? OP_MoveLe : OP_MoveLt;
+          sqlite3VdbeAddOp(v, op, pLevel->iCur, brk);
         }else{
           sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
         }
@@ -1083,10 +1072,8 @@ WhereInfo *sqlite3WhereBegin(
           sqlite3VdbeAddOp(v, OP_MemStore, pLevel->iMem, 1);
           testOp = OP_IdxLT;
         }else{
-          sqlite3VdbeAddOp(v, OP_MoveTo, pLevel->iCur, brk);
-          if( !geFlag ){
-            sqlite3VdbeChangeP3(v, -1, "+", P3_STATIC);
-          }
+          int op = geFlag ? OP_MoveGe : OP_MoveGt;
+          sqlite3VdbeAddOp(v, op, pLevel->iCur, brk);
         }
       }else if( pLevel->bRev ){
         testOp = OP_Noop;
@@ -1112,7 +1099,7 @@ WhereInfo *sqlite3WhereBegin(
       if( i==pTabList->nSrc-1 && pushKey ){
         haveKey = 1;
       }else{
-        sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
+        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
         haveKey = 0;
       }
 
@@ -1135,7 +1122,7 @@ WhereInfo *sqlite3WhereBegin(
       }
       if( haveKey ){
         haveKey = 0;
-        sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
+        sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
       }
       sqlite3ExprIfFalse(pParse, aExpr[j].p, cont, 1);
       aExpr[j].p = 0;
@@ -1158,7 +1145,7 @@ WhereInfo *sqlite3WhereBegin(
           ** no outer joins with DELETE and UPDATE.
           */
           haveKey = 0;
-          sqlite3VdbeAddOp(v, OP_MoveTo, iCur, 0);
+          sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
         }
         sqlite3ExprIfFalse(pParse, aExpr[j].p, cont, 1);
         aExpr[j].p = 0;
diff --git a/test/where.test b/test/where.test
index d0c73884fd..465fb81696 100644
--- a/test/where.test
+++ b/test/where.test
@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing the use of indices in WHERE clases.
 #
-# $Id: where.test,v 1.18 2004/05/19 13:13:08 drh Exp $
+# $Id: where.test,v 1.19 2004/05/19 14:56:57 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -140,6 +140,7 @@ do_test where-1.25 {
 do_test where-1.27 {
   count {SELECT w FROM t1 WHERE x=3 AND y+1==122}
 } {10 17}
+
 do_test where-1.28 {
   count {SELECT w FROM t1 WHERE x+1=4 AND y+1==122}
 } {10 99}