From 66181ce2b8504d5a11e4222e1c87beccb2c1799b Mon Sep 17 00:00:00 2001
From: drh <>
Date: Thu, 31 Mar 2022 20:04:49 +0000
Subject: [PATCH 1/2] Rename Vdbe.iVdbeMagic to eVdbeState.  Remove unnecessary
 states.  This is a preliminary step toward splitting RUN_STATE out into
 several other states.

FossilOrigin-Name: ff91191d232305d44ae6c0fbca2542a749422dc716fa1fd5d54f58c7d6052c14
---
 manifest      | 21 ++++++++++++---------
 manifest.uuid |  2 +-
 src/vdbe.c    |  2 +-
 src/vdbeInt.h | 13 ++++++-------
 src/vdbeapi.c |  6 +++---
 src/vdbeaux.c | 38 +++++++++++++++++---------------------
 6 files changed, 40 insertions(+), 42 deletions(-)

diff --git a/manifest b/manifest
index a443d0fbce..d3dfb5782a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sharmless\scompiler\swarnings.
-D 2022-03-31T16:09:13.558
+C Rename\sVdbe.iVdbeMagic\sto\seVdbeState.\s\sRemove\sunnecessary\sstates.\s\sThis\sis\na\spreliminary\sstep\stoward\ssplitting\sRUN_STATE\sout\sinto\sseveral\sother\sstates.
+D 2022-03-31T20:04:49.855
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -624,11 +624,11 @@ F src/upsert.c 8789047a8f0a601ea42fa0256d1ba3190c13746b6ba940fe2d25643a7e991937
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 602fe229f32a96ceccae4f40824129669582096f7c355f53dbac156c9fecef23
 F src/vacuum.c 6c38ddc52f0619865c91dae9c441d4d48bf3040d7dc1bc5b22da1e45547ed0b3
-F src/vdbe.c af4a5e9d64dbcc484be1fa4609b655577f81ee2cd40b61e96bece6d43718ae91
+F src/vdbe.c c7982c468cf39e3ad690da427aa72d43744debc32cea943849b688c17dfe2bff
 F src/vdbe.h a1d0e3b934e835e73edd146f2e7c4eadb711b5c9875c18159a57483fd78e550e
-F src/vdbeInt.h 8dd91427155a38ec06e9ecbde07e33f21bc02e101625191e7613f883e379a363
-F src/vdbeapi.c d41dedcf05f4b0ee3f0a2ce4f8316631fef5391c2d5705b4a0b48156b8061c0b
-F src/vdbeaux.c 45a94316496a200a1d3a29b014fbbc7fc44860c026f768b2d0fcc108e92536d4
+F src/vdbeInt.h fe6987d90048eee26bf0e9a2498ff3f2c5d4149b0d6e78b9fcc6bce13274faae
+F src/vdbeapi.c 0bfeb0ebfb2b064b97bcb389a92f9f819bacc2ae70c819c6976157616f48c31c
+F src/vdbeaux.c 4260b1016c9e47a20c75f7d311c4bf1fe5b0efa9dafa2f72f7959fcb0517792b
 F src/vdbeblob.c 5e61ce31aca17db8fb60395407457a8c1c7fb471dde405e0cd675974611dcfcd
 F src/vdbemem.c 512499e51eb7cbe1d886031f19ab6f3e05655a0b25655991af01b61a631a78f7
 F src/vdbesort.c 43756031ca7430f7aec3ef904824a7883c4ede783e51f280d99b9b65c0796e35
@@ -1945,8 +1945,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P f2d9262e4427ab37ba26c004fc7a4790c86c1856d695a6b4ec3e72732ea54c09
-R d2182f02ef1334fdc5f699b0ef49ddd5
+P b916087aacba53530d2bd19eef2a4fd7a253bf7fa87b49e0df17f7987d7164ae
+R 3c60b6ccbc6ab91e39cbf56c4038bfa8
+T *branch * vdbe-state-refactor
+T *sym-vdbe-state-refactor *
+T -sym-trunk *
 U drh
-Z 8f84c3af05b1ca72966bc5e0edb8cacb
+Z 839815ce9594c9953a4b8872bf63aa11
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 5456276fa0..8b300102c5 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b916087aacba53530d2bd19eef2a4fd7a253bf7fa87b49e0df17f7987d7164ae
\ No newline at end of file
+ff91191d232305d44ae6c0fbca2542a749422dc716fa1fd5d54f58c7d6052c14
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index ec227f884a..44a60e2bbf 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -740,7 +740,7 @@ int sqlite3VdbeExec(
 #endif
   /*** INSERT STACK UNION HERE ***/
 
-  assert( p->iVdbeMagic==VDBE_MAGIC_RUN );  /* sqlite3_step() verifies this */
+  assert( p->eVdbeState==VDBE_RUN_STATE );  /* sqlite3_step() verifies this */
   sqlite3VdbeEnter(p);
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   if( db->xProgress ){
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 45720b6a55..aba378f397 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -417,7 +417,6 @@ struct Vdbe {
   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
   Parse *pParse;          /* Parsing context used to create this Vdbe */
   ynVar nVar;             /* Number of entries in aVar[] */
-  u32 iVdbeMagic;         /* Magic number defining state of the SQL statement */
   int nMem;               /* Number of memory locations currently allocated */
   int nCursor;            /* Number of slots in apCsr[] */
   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
@@ -456,6 +455,7 @@ struct Vdbe {
   u8 minWriteFileFormat;  /* Minimum file format for writable database files */
   u8 prepFlags;           /* SQLITE_PREPARE_* flags */
   u8 doingRerun;          /* True if rerunning after an auto-reprepare */
+  u8 eVdbeState;          /* On of the VDBE_*_STATE values */
   bft expired:2;          /* 1: recompile VM immediately  2: when convenient */
   bft explain:2;          /* True if EXPLAIN present on SQL command */
   bft changeCntOn:1;      /* True to update the change-counter */
@@ -486,13 +486,12 @@ struct Vdbe {
 };
 
 /*
-** The following are allowed values for Vdbe.magic
+** The following are allowed values for Vdbe.eVdbeState
 */
-#define VDBE_MAGIC_INIT     0x16bceaa5    /* Building a VDBE program */
-#define VDBE_MAGIC_RUN      0x2df20da3    /* VDBE is ready to execute */
-#define VDBE_MAGIC_HALT     0x319c2973    /* VDBE has completed execution */
-#define VDBE_MAGIC_RESET    0x48fa9f76    /* Reset and ready to run again */
-#define VDBE_MAGIC_DEAD     0x5606c3c8    /* The VDBE has been deallocated */
+#define VDBE_INIT_STATE     0   /* Prepared statement under construction */
+#define VDBE_READY_STATE    1   /* Ready to run but not yet started */
+#define VDBE_RUN_STATE      2   /* Run in progress */
+#define VDBE_HALT_STATE     3   /* Finished.  Need reset() or finalize() */
 
 /*
 ** Structure used to store the context required by the 
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 7567b89945..49d9a1d57c 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -643,7 +643,7 @@ static int sqlite3Step(Vdbe *p){
   int rc;
 
   assert(p);
-  if( p->iVdbeMagic!=VDBE_MAGIC_RUN ){
+  if( p->eVdbeState!=VDBE_RUN_STATE ){
     /* We used to require that sqlite3_reset() be called before retrying
     ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
     ** with version 3.7.0, we changed this so that sqlite3_reset() would
@@ -1428,7 +1428,7 @@ static int vdbeUnbind(Vdbe *p, int i){
     return SQLITE_MISUSE_BKPT;
   }
   sqlite3_mutex_enter(p->db->mutex);
-  if( p->iVdbeMagic!=VDBE_MAGIC_RUN || p->pc>=0 ){
+  if( p->eVdbeState!=VDBE_RUN_STATE || p->pc>=0 ){
     sqlite3Error(p->db, SQLITE_MISUSE);
     sqlite3_mutex_leave(p->db->mutex);
     sqlite3_log(SQLITE_MISUSE, 
@@ -1781,7 +1781,7 @@ int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
 */
 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
   Vdbe *v = (Vdbe*)pStmt;
-  return v!=0 && v->iVdbeMagic==VDBE_MAGIC_RUN && v->pc>=0;
+  return v!=0 && v->eVdbeState==VDBE_RUN_STATE && v->pc>=0;
 }
 
 /*
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index c5024efb13..1ce4c14ace 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -35,7 +35,7 @@ Vdbe *sqlite3VdbeCreate(Parse *pParse){
   p->pNext = db->pVdbe;
   p->pPrev = 0;
   db->pVdbe = p;
-  p->iVdbeMagic = VDBE_MAGIC_INIT;
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   p->pParse = pParse;
   pParse->pVdbe = p;
   assert( pParse->aLabel==0 );
@@ -236,7 +236,7 @@ int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   VdbeOp *pOp;
 
   i = p->nOp;
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   assert( op>=0 && op<0xff );
   if( p->nOpAlloc<=i ){
     return growOp3(p, op, p1, p2, p3);
@@ -568,7 +568,7 @@ static SQLITE_NOINLINE void resizeResolveLabel(Parse *p, Vdbe *v, int j){
 void sqlite3VdbeResolveLabel(Vdbe *v, int x){
   Parse *p = v->pParse;
   int j = ADDR(x);
-  assert( v->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( v->eVdbeState==VDBE_INIT_STATE );
   assert( j<-p->nLabel );
   assert( j>=0 );
 #ifdef SQLITE_DEBUG
@@ -878,7 +878,7 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
 ** Return the address of the next instruction to be inserted.
 */
 int sqlite3VdbeCurrentAddr(Vdbe *p){
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   return p->nOp;
 }
 
@@ -963,7 +963,7 @@ VdbeOp *sqlite3VdbeAddOpList(
   int i;
   VdbeOp *pOut, *pFirst;
   assert( nOp>0 );
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   if( p->nOp + nOp > p->nOpAlloc && growOpArray(p, nOp) ){
     return 0;
   }
@@ -1289,7 +1289,7 @@ void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
   sqlite3 *db;
   assert( p!=0 );
   db = p->db;
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   assert( p->aOp!=0 || db->mallocFailed );
   if( db->mallocFailed ){
     if( n!=P4_VTAB ) freeP4(db, n, (void*)*(char**)&zP4);
@@ -1417,7 +1417,7 @@ VdbeOp *sqlite3VdbeGetOp(Vdbe *p, int addr){
   /* C89 specifies that the constant "dummy" will be initialized to all
   ** zeros, which is correct.  MSVC generates a warning, nevertheless. */
   static VdbeOp dummy;  /* Ignore the MSVC warning about no initializer */
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   if( addr<0 ){
     addr = p->nOp - 1;
   }
@@ -2119,7 +2119,7 @@ int sqlite3VdbeList(
   Op *pOp;                             /* Current opcode */
 
   assert( p->explain );
-  assert( p->iVdbeMagic==VDBE_MAGIC_RUN );
+  assert( p->eVdbeState==VDBE_RUN_STATE );
   assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY || p->rc==SQLITE_NOMEM );
 
   /* Even though this opcode does not use dynamic strings for
@@ -2299,14 +2299,13 @@ void sqlite3VdbeRewind(Vdbe *p){
   int i;
 #endif
   assert( p!=0 );
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT || p->iVdbeMagic==VDBE_MAGIC_RESET );
+  assert( p->eVdbeState==VDBE_INIT_STATE || p->eVdbeState==VDBE_HALT_STATE );
 
   /* There should be at least one opcode.
   */
   assert( p->nOp>0 );
 
-  /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */
-  p->iVdbeMagic = VDBE_MAGIC_RUN;
+  p->eVdbeState = VDBE_RUN_STATE;
 
 #ifdef SQLITE_DEBUG
   for(i=0; i<p->nMem; i++){
@@ -2362,7 +2361,7 @@ void sqlite3VdbeMakeReady(
   assert( p!=0 );
   assert( p->nOp>0 );
   assert( pParse!=0 );
-  assert( p->iVdbeMagic==VDBE_MAGIC_INIT );
+  assert( p->eVdbeState==VDBE_INIT_STATE );
   assert( pParse==p->pParse );
   p->pVList = pParse->pVList;
   pParse->pVList =  0;
@@ -3041,7 +3040,7 @@ int sqlite3VdbeHalt(Vdbe *p){
   ** one, or the complete transaction if there is no statement transaction.
   */
 
-  if( p->iVdbeMagic!=VDBE_MAGIC_RUN ){
+  if( p->eVdbeState!=VDBE_RUN_STATE ){
     return SQLITE_OK;
   }
   if( db->mallocFailed ){
@@ -3208,7 +3207,7 @@ int sqlite3VdbeHalt(Vdbe *p){
     assert( db->nVdbeRead>=db->nVdbeWrite );
     assert( db->nVdbeWrite>=0 );
   }
-  p->iVdbeMagic = VDBE_MAGIC_HALT;
+  p->eVdbeState = VDBE_HALT_STATE;
   checkActiveVdbeCnt(db);
   if( db->mallocFailed ){
     p->rc = SQLITE_NOMEM_BKPT;
@@ -3290,8 +3289,8 @@ static void vdbeInvokeSqllog(Vdbe *v){
 ** again.
 **
 ** To look at it another way, this routine resets the state of the
-** virtual machine from VDBE_MAGIC_RUN or VDBE_MAGIC_HALT back to
-** VDBE_MAGIC_INIT.
+** virtual machine from VDBE_RUN_STATE or VDBE_HALT_STATE back to
+** VDBE_READY_STATE.
 */
 int sqlite3VdbeReset(Vdbe *p){
 #if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
@@ -3382,7 +3381,6 @@ int sqlite3VdbeReset(Vdbe *p){
     }
   }
 #endif
-  p->iVdbeMagic = VDBE_MAGIC_RESET;
   return p->rc & db->errMask;
 }
  
@@ -3392,7 +3390,7 @@ int sqlite3VdbeReset(Vdbe *p){
 */
 int sqlite3VdbeFinalize(Vdbe *p){
   int rc = SQLITE_OK;
-  if( p->iVdbeMagic==VDBE_MAGIC_RUN || p->iVdbeMagic==VDBE_MAGIC_HALT ){
+  if( p->eVdbeState==VDBE_RUN_STATE || p->eVdbeState==VDBE_HALT_STATE ){
     rc = sqlite3VdbeReset(p);
     assert( (rc & p->db->errMask)==rc );
   }
@@ -3456,7 +3454,7 @@ void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
     vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
     sqlite3DbFree(db, pSub);
   }
-  if( p->iVdbeMagic!=VDBE_MAGIC_INIT ){
+  if( p->eVdbeState!=VDBE_INIT_STATE ){
     releaseMemArray(p->aVar, p->nVar);
     if( p->pVList ) sqlite3DbFreeNN(db, p->pVList);
     if( p->pFree ) sqlite3DbFreeNN(db, p->pFree);
@@ -3503,8 +3501,6 @@ void sqlite3VdbeDelete(Vdbe *p){
   if( p->pNext ){
     p->pNext->pPrev = p->pPrev;
   }
-  p->iVdbeMagic = VDBE_MAGIC_DEAD;
-  p->db = 0;
   sqlite3DbFreeNN(db, p);
 }
 

From 99a218282c42057ada2c187dc28f47442ce78751 Mon Sep 17 00:00:00 2001
From: drh <>
Date: Thu, 31 Mar 2022 21:15:09 +0000
Subject: [PATCH 2/2] Split out the RUN state into separate READY and RUN
 states.

FossilOrigin-Name: d698826b08b88e227eb83f84b3cdb19f17306b532eccfa162090abccdf3c63d8
---
 manifest      |  17 +++----
 manifest.uuid |   2 +-
 src/vdbeapi.c | 137 +++++++++++++++++++++++++++-----------------------
 src/vdbeaux.c |  31 ++++++------
 4 files changed, 97 insertions(+), 90 deletions(-)

diff --git a/manifest b/manifest
index d3dfb5782a..ac0d69c54e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Rename\sVdbe.iVdbeMagic\sto\seVdbeState.\s\sRemove\sunnecessary\sstates.\s\sThis\sis\na\spreliminary\sstep\stoward\ssplitting\sRUN_STATE\sout\sinto\sseveral\sother\sstates.
-D 2022-03-31T20:04:49.855
+C Split\sout\sthe\sRUN\sstate\sinto\sseparate\sREADY\sand\sRUN\sstates.
+D 2022-03-31T21:15:09.341
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -627,8 +627,8 @@ F src/vacuum.c 6c38ddc52f0619865c91dae9c441d4d48bf3040d7dc1bc5b22da1e45547ed0b3
 F src/vdbe.c c7982c468cf39e3ad690da427aa72d43744debc32cea943849b688c17dfe2bff
 F src/vdbe.h a1d0e3b934e835e73edd146f2e7c4eadb711b5c9875c18159a57483fd78e550e
 F src/vdbeInt.h fe6987d90048eee26bf0e9a2498ff3f2c5d4149b0d6e78b9fcc6bce13274faae
-F src/vdbeapi.c 0bfeb0ebfb2b064b97bcb389a92f9f819bacc2ae70c819c6976157616f48c31c
-F src/vdbeaux.c 4260b1016c9e47a20c75f7d311c4bf1fe5b0efa9dafa2f72f7959fcb0517792b
+F src/vdbeapi.c bdc977e721fbadb9b075f8f4eb5f4ac5289eb2bffc0786ffae303e915580484a
+F src/vdbeaux.c 6c76956b969cdb65b52fe120e1e5424868ec4473f454dd81039e5b07a2b44ee4
 F src/vdbeblob.c 5e61ce31aca17db8fb60395407457a8c1c7fb471dde405e0cd675974611dcfcd
 F src/vdbemem.c 512499e51eb7cbe1d886031f19ab6f3e05655a0b25655991af01b61a631a78f7
 F src/vdbesort.c 43756031ca7430f7aec3ef904824a7883c4ede783e51f280d99b9b65c0796e35
@@ -1945,11 +1945,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b916087aacba53530d2bd19eef2a4fd7a253bf7fa87b49e0df17f7987d7164ae
-R 3c60b6ccbc6ab91e39cbf56c4038bfa8
-T *branch * vdbe-state-refactor
-T *sym-vdbe-state-refactor *
-T -sym-trunk *
+P ff91191d232305d44ae6c0fbca2542a749422dc716fa1fd5d54f58c7d6052c14
+R ec623ff49fd7a3945e7e6cf4e06ba68c
 U drh
-Z 839815ce9594c9953a4b8872bf63aa11
+Z 2cbaf76e3cc43bc83d2f6fc2647ea3ec
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 8b300102c5..06fb3a929c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ff91191d232305d44ae6c0fbca2542a749422dc716fa1fd5d54f58c7d6052c14
\ No newline at end of file
+d698826b08b88e227eb83f84b3cdb19f17306b532eccfa162090abccdf3c63d8
\ No newline at end of file
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 49d9a1d57c..4c8078be3f 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -642,35 +642,6 @@ static int sqlite3Step(Vdbe *p){
   sqlite3 *db;
   int rc;
 
-  assert(p);
-  if( p->eVdbeState!=VDBE_RUN_STATE ){
-    /* We used to require that sqlite3_reset() be called before retrying
-    ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
-    ** with version 3.7.0, we changed this so that sqlite3_reset() would
-    ** be called automatically instead of throwing the SQLITE_MISUSE error.
-    ** This "automatic-reset" change is not technically an incompatibility, 
-    ** since any application that receives an SQLITE_MISUSE is broken by
-    ** definition.
-    **
-    ** Nevertheless, some published applications that were originally written
-    ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE 
-    ** returns, and those were broken by the automatic-reset change.  As a
-    ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
-    ** legacy behavior of returning SQLITE_MISUSE for cases where the 
-    ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
-    ** or SQLITE_BUSY error.
-    */
-#ifdef SQLITE_OMIT_AUTORESET
-    if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
-      sqlite3_reset((sqlite3_stmt*)p);
-    }else{
-      return SQLITE_MISUSE_BKPT;
-    }
-#else
-    sqlite3_reset((sqlite3_stmt*)p);
-#endif
-  }
-
   /* Check that malloc() has not failed. If it has, return early. */
   db = p->db;
   if( db->mallocFailed ){
@@ -678,45 +649,83 @@ static int sqlite3Step(Vdbe *p){
     return SQLITE_NOMEM_BKPT;
   }
 
-  if( p->pc<0 && p->expired ){
-    p->rc = SQLITE_SCHEMA;
-    rc = SQLITE_ERROR;
-    if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
-      /* If this statement was prepared using saved SQL and an 
-      ** error has occurred, then return the error code in p->rc to the
-      ** caller. Set the error code in the database handle to the same value.
-      */ 
-      rc = sqlite3VdbeTransferError(p);
-    }
-    goto end_of_step;
-  }
-  if( p->pc<0 ){
-    /* If there are no other statements currently running, then
-    ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
-    ** from interrupting a statement that has not yet started.
-    */
-    if( db->nVdbeActive==0 ){
-      AtomicStore(&db->u1.isInterrupted, 0);
-    }
+  assert(p);
+  if( p->eVdbeState!=VDBE_RUN_STATE ){
+    restart_step:
+    if( p->eVdbeState==VDBE_READY_STATE ){
+      if( p->expired ){
+        p->rc = SQLITE_SCHEMA;
+        rc = SQLITE_ERROR;
+        if( (p->prepFlags & SQLITE_PREPARE_SAVESQL)!=0 ){
+          /* If this statement was prepared using saved SQL and an 
+          ** error has occurred, then return the error code in p->rc to the
+          ** caller. Set the error code in the database handle to the same
+          ** value.
+          */ 
+          rc = sqlite3VdbeTransferError(p);
+        }
+        goto end_of_step;
+      }
 
-    assert( db->nVdbeWrite>0 || db->autoCommit==0 
-        || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
-    );
+      /* If there are no other statements currently running, then
+      ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
+      ** from interrupting a statement that has not yet started.
+      */
+      if( db->nVdbeActive==0 ){
+        AtomicStore(&db->u1.isInterrupted, 0);
+      }
+
+      assert( db->nVdbeWrite>0 || db->autoCommit==0 
+          || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
+      );
 
 #ifndef SQLITE_OMIT_TRACE
-    if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
-        && !db->init.busy && p->zSql ){
-      sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
-    }else{
-      assert( p->startTime==0 );
-    }
+      if( (db->mTrace & (SQLITE_TRACE_PROFILE|SQLITE_TRACE_XPROFILE))!=0
+          && !db->init.busy && p->zSql ){
+        sqlite3OsCurrentTimeInt64(db->pVfs, &p->startTime);
+      }else{
+        assert( p->startTime==0 );
+      }
 #endif
 
-    db->nVdbeActive++;
-    if( p->readOnly==0 ) db->nVdbeWrite++;
-    if( p->bIsReader ) db->nVdbeRead++;
-    p->pc = 0;
+      db->nVdbeActive++;
+      if( p->readOnly==0 ) db->nVdbeWrite++;
+      if( p->bIsReader ) db->nVdbeRead++;
+      p->pc = 0;
+      p->eVdbeState = VDBE_RUN_STATE;
+    }else
+
+    if( p->eVdbeState==VDBE_HALT_STATE ){
+      /* We used to require that sqlite3_reset() be called before retrying
+      ** sqlite3_step() after any error or after SQLITE_DONE.  But beginning
+      ** with version 3.7.0, we changed this so that sqlite3_reset() would
+      ** be called automatically instead of throwing the SQLITE_MISUSE error.
+      ** This "automatic-reset" change is not technically an incompatibility, 
+      ** since any application that receives an SQLITE_MISUSE is broken by
+      ** definition.
+      **
+      ** Nevertheless, some published applications that were originally written
+      ** for version 3.6.23 or earlier do in fact depend on SQLITE_MISUSE 
+      ** returns, and those were broken by the automatic-reset change.  As a
+      ** a work-around, the SQLITE_OMIT_AUTORESET compile-time restores the
+      ** legacy behavior of returning SQLITE_MISUSE for cases where the 
+      ** previous sqlite3_step() returned something other than a SQLITE_LOCKED
+      ** or SQLITE_BUSY error.
+      */
+#ifdef SQLITE_OMIT_AUTORESET
+      if( (rc = p->rc&0xff)==SQLITE_BUSY || rc==SQLITE_LOCKED ){
+        sqlite3_reset((sqlite3_stmt*)p);
+      }else{
+        return SQLITE_MISUSE_BKPT;
+      }
+#else
+      sqlite3_reset((sqlite3_stmt*)p);
+#endif
+      assert( p->eVdbeState==VDBE_READY_STATE );
+      goto restart_step;
+    }
   }
+
 #ifdef SQLITE_DEBUG
   p->rcApp = SQLITE_OK;
 #endif
@@ -1428,7 +1437,7 @@ static int vdbeUnbind(Vdbe *p, int i){
     return SQLITE_MISUSE_BKPT;
   }
   sqlite3_mutex_enter(p->db->mutex);
-  if( p->eVdbeState!=VDBE_RUN_STATE || p->pc>=0 ){
+  if( p->eVdbeState!=VDBE_READY_STATE ){
     sqlite3Error(p->db, SQLITE_MISUSE);
     sqlite3_mutex_leave(p->db->mutex);
     sqlite3_log(SQLITE_MISUSE, 
@@ -1781,7 +1790,7 @@ int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt){
 */
 int sqlite3_stmt_busy(sqlite3_stmt *pStmt){
   Vdbe *v = (Vdbe*)pStmt;
-  return v!=0 && v->eVdbeState==VDBE_RUN_STATE && v->pc>=0;
+  return v!=0 && v->eVdbeState==VDBE_RUN_STATE;
 }
 
 /*
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 1ce4c14ace..ce92999cdf 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2299,13 +2299,15 @@ void sqlite3VdbeRewind(Vdbe *p){
   int i;
 #endif
   assert( p!=0 );
-  assert( p->eVdbeState==VDBE_INIT_STATE || p->eVdbeState==VDBE_HALT_STATE );
+  assert( p->eVdbeState==VDBE_INIT_STATE
+       || p->eVdbeState==VDBE_READY_STATE
+       || p->eVdbeState==VDBE_HALT_STATE );
 
   /* There should be at least one opcode.
   */
   assert( p->nOp>0 );
 
-  p->eVdbeState = VDBE_RUN_STATE;
+  p->eVdbeState = VDBE_READY_STATE;
 
 #ifdef SQLITE_DEBUG
   for(i=0; i<p->nMem; i++){
@@ -2558,9 +2560,7 @@ static void closeAllCursors(Vdbe *p){
   }
   assert( p->nFrame==0 );
   closeCursorsInFrame(p);
-  if( p->aMem ){
-    releaseMemArray(p->aMem, p->nMem);
-  }
+  releaseMemArray(p->aMem, p->nMem);
   while( p->pDelFrame ){
     VdbeFrame *pDel = p->pDelFrame;
     p->pDelFrame = pDel->pParent;
@@ -3051,7 +3051,7 @@ int sqlite3VdbeHalt(Vdbe *p){
 
   /* No commit or rollback needed if the program never started or if the
   ** SQL statement does not read or write a database file.  */
-  if( p->pc>=0 && p->bIsReader ){
+  if( p->bIsReader ){
     int mrc;   /* Primary error code from p->rc */
     int eStatementOp = 0;
     int isSpecialError;            /* Set to true if a 'special' error */
@@ -3199,14 +3199,12 @@ int sqlite3VdbeHalt(Vdbe *p){
   }
 
   /* We have successfully halted and closed the VM.  Record this fact. */
-  if( p->pc>=0 ){
-    db->nVdbeActive--;
-    if( !p->readOnly ) db->nVdbeWrite--;
-    if( p->bIsReader ) db->nVdbeRead--;
-    assert( db->nVdbeActive>=db->nVdbeRead );
-    assert( db->nVdbeRead>=db->nVdbeWrite );
-    assert( db->nVdbeWrite>=0 );
-  }
+  db->nVdbeActive--;
+  if( !p->readOnly ) db->nVdbeWrite--;
+  if( p->bIsReader ) db->nVdbeRead--;
+  assert( db->nVdbeActive>=db->nVdbeRead );
+  assert( db->nVdbeRead>=db->nVdbeWrite );
+  assert( db->nVdbeWrite>=0 );
   p->eVdbeState = VDBE_HALT_STATE;
   checkActiveVdbeCnt(db);
   if( db->mallocFailed ){
@@ -3390,7 +3388,10 @@ int sqlite3VdbeReset(Vdbe *p){
 */
 int sqlite3VdbeFinalize(Vdbe *p){
   int rc = SQLITE_OK;
-  if( p->eVdbeState==VDBE_RUN_STATE || p->eVdbeState==VDBE_HALT_STATE ){
+  assert( VDBE_RUN_STATE>VDBE_READY_STATE );
+  assert( VDBE_HALT_STATE>VDBE_READY_STATE );
+  assert( VDBE_INIT_STATE<VDBE_READY_STATE );
+  if( p->eVdbeState>=VDBE_READY_STATE ){
     rc = sqlite3VdbeReset(p);
     assert( (rc & p->db->errMask)==rc );
   }