From 6f58f7069ba7c2cb5844893ad4a511524261e7ef Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Sun, 8 Jan 2006 05:26:41 +0000
Subject: [PATCH] Remove some cruft from the VDBE.  Bring comments up to date.
 (CVS 2888)

FossilOrigin-Name: 41aef6496a10c81e1095408dc8f69740d6ea7627
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/vdbe.c    | 33 ++++++++++++++++++---------------
 3 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/manifest b/manifest
index 27a9c4b508..49cdf3cf7a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Reduce\smemory\srequirements\sfor\sORDER\sBY\scombined\swith\sLIMIT.\s\sTicket\s#1586.\s(CVS\s2887)
-D 2006-01-08T05:02:55
+C Remove\ssome\scruft\sfrom\sthe\sVDBE.\s\sBring\scomments\sup\sto\sdate.\s(CVS\s2888)
+D 2006-01-08T05:26:41
 F Makefile.in c79fbdaa264c6afcd435f2fb492551de5a8cf80d
 F Makefile.linux-gcc aee18d8a05546dcf1888bd4547e442008a49a092
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -84,7 +84,7 @@ F src/update.c 29ba0385c8639803cd8e6e616e99096a0bc10443
 F src/utf.c b7bffac4260177ae7f83c01d025fe0f5ed70ce71
 F src/util.c 8a3ef3c1b345cdadcee33ce4537c63bb0fda0ed8
 F src/vacuum.c a7301804d4f849da0ce9d869219c71c6d621c34e
-F src/vdbe.c 87a796e2889283b681be71076fa6b6318561f2bd
+F src/vdbe.c 21a1cb8500e5482aa4b670ce4788b7474d3b8bb7
 F src/vdbe.h 8729a4ee16ff9aeab2af9667df3cf300ff978e13
 F src/vdbeInt.h 5451cf71f229e366ac543607c0a17f36e5737ea9
 F src/vdbeapi.c 7335569b1bad946ba53892384b4b1534e877b1ee
@@ -335,7 +335,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 0ae461313c1642a49a9f6cda608c42c7c0053ce4
-R 79c569a066edb0857c89ee545cff9b3e
+P 55e703ecac6e03d7364c2d919ba18d7293d6b7f6
+R b966bf179439ff438aedbc30041f68e4
 U drh
-Z e2eb2297d27afb66b9b69713714cfa42
+Z 3ef314255d1b0a31cdba3fda0e06ec3c
diff --git a/manifest.uuid b/manifest.uuid
index dd1dcb56b2..51c273ef38 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-55e703ecac6e03d7364c2d919ba18d7293d6b7f6
\ No newline at end of file
+41aef6496a10c81e1095408dc8f69740d6ea7627
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index fd1d942226..22e9393534 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 1.516 2006/01/07 18:48:26 drh Exp $
+** $Id: vdbe.c,v 1.517 2006/01/08 05:26:41 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -4277,14 +4277,12 @@ case OP_MemMax: {        /* no-push */
 }
 #endif /* SQLITE_OMIT_AUTOINCREMENT */
 
-/* Opcode: MemIncr P1 P2 *
+/* Opcode: MemIncr P1 * *
 **
-** Increment the integer valued memory cell P1 by 1.  If P2 is not zero
-** and the result after the increment is exactly 0, then jump
-** to P2.
+** Increment the integer valued memory cell P1 by 1.
 **
-** This instruction throws an error if the memory cell is not initially
-** an integer.
+** It is illegal to use this instruction on a memory cell that does
+** not contain an integer.  An assertion fault will result if you try.
 */
 case OP_MemIncr: {        /* no-push */
   int i = pOp->p1;
@@ -4293,24 +4291,25 @@ case OP_MemIncr: {        /* no-push */
   pMem = &p->aMem[i];
   assert( pMem->flags==MEM_Int );
   pMem->i++;
-  if( pOp->p2>0 && pMem->i==0 ){
-     pc = pOp->p2 - 1;
-  }
+  assert( pOp->p2==0 );
   break;
 }
 
 /* Opcode: IfMemPos P1 P2 *
 **
 ** If the value of memory cell P1 is 1 or greater, jump to P2.  If
-** the memory cell holds an integer of 0 or less or if it holds something
-** that is not an integer, then fall thru.
+** the memory cell holds an integer of 0 or less.
+**
+** It is illegal to use this instruction on a memory cell that does
+** not contain an integer.  An assertion fault will result if you try.
 */
 case OP_IfMemPos: {        /* no-push */
   int i = pOp->p1;
   Mem *pMem;
   assert( i>=0 && i<p->nMem );
   pMem = &p->aMem[i];
-  if( pMem->flags==MEM_Int && pMem->i>0 ){
+  assert( pMem->flags==MEM_Int );
+  if( pMem->i>0 ){
      pc = pOp->p2 - 1;
   }
   break;
@@ -4318,14 +4317,18 @@ case OP_IfMemPos: {        /* no-push */
 
 /* Opcode: IfMemZero P1 P2 *
 **
-** If the value of memory cell P1 is exactly 0, jump to P2.
+** If the value of memory cell P1 is exactly 0, jump to P2. 
+**
+** It is illegal to use this instruction on a memory cell that does
+** not contain an integer.  An assertion fault will result if you try.
 */
 case OP_IfMemZero: {        /* no-push */
   int i = pOp->p1;
   Mem *pMem;
   assert( i>=0 && i<p->nMem );
   pMem = &p->aMem[i];
-  if( pMem->flags==MEM_Int && pMem->i==0 ){
+  assert( pMem->flags==MEM_Int );
+  if( pMem->i==0 ){
      pc = pOp->p2 - 1;
   }
   break;