diff --git a/manifest b/manifest
index 6120e9f28c..da44960d82 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Clean\sup\sthe\slocking\sin\sthe\sbtree\slogic.\s(CVS\s4316)
-D 2007-08-28T22:24:35
+C The\sshared_err\stest\sruns\swith\sno\serrors.\s\sBut\sa\spotential\sdeadlock\shas\sbeen\ndiscovered\sand\sis\sstill\sunfixed.\s(CVS\s4317)
+D 2007-08-28T23:28:08
 F Makefile.in bfcc303429a5d9dcd552d807ee016c77427418c3
 F Makefile.linux-gcc 65241babba6faf1152bf86574477baab19190499
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -80,9 +80,9 @@ F src/alter.c fd78c6005456c727a6cb7c01c5266f2aacf6d401
 F src/analyze.c a14237d869c6bea0846493b59317e4097e81a0b6
 F src/attach.c a52225c75b107be8c5bc144a2b6d20201be3f8f8
 F src/auth.c 083c1205b45e3f52291ec539d396b4fc557856b3
-F src/btmutex.c 3a19fcb311d0d09e63d397779be881d4273f4518
-F src/btree.c 8796aa42fd16feb587844489a0fce8c66e52ac02
-F src/btree.h a8fb26c56b745b57446c2bf29133619261313051
+F src/btmutex.c fc9d8316fccf491f1011ddc4087338f0ce3b5263
+F src/btree.c 0241f79766d718d524a28857c3899aee7a728194
+F src/btree.h 03895d1da697e616d918856a26ec63ef8f5aa497
 F src/btreeInt.h 5b1bc919cb80f0dd6baec1cdbae737f9806a7e3b
 F src/build.c 99b0b0c44ce7673c00d8c0c97ce536e3b796328b
 F src/callback.c a542236a68060caad378efa30006ca46cf77b1b2
@@ -162,11 +162,11 @@ F src/update.c e89b980b443d44b68bfc0b1746cdb6308e049ac9
 F src/utf.c 4af6259d5906b5a1bf3035cc387c4d7907bdd56e
 F src/util.c 3f9c0387b54f977726790f52ab92cd3d9379b367
 F src/vacuum.c 5ec133b69edf581a232af7e2b01f45c9f2b8be32
-F src/vdbe.c 62d210babaac906a5847d7bd4c71e7b114595e85
+F src/vdbe.c f578e7f0905489ced1f05bc418dd51c0f79f9a04
 F src/vdbe.h 498e9ddade4baf70f2fc39e585670131dde07caa
-F src/vdbeInt.h a9dcd0688783abbd60981aff7ecc5b57a9559765
+F src/vdbeInt.h 630145b9bfaa19190ab491f52658a7db550f2247
 F src/vdbeapi.c bdd0aea216744482dd1b7fab56de18ba5b6fbdf4
-F src/vdbeaux.c 0bbc8fbb6bcd610e98ce8eef77d0db660710f9dd
+F src/vdbeaux.c 347d2c1d68f326c90c27660da86849c51134fe1d
 F src/vdbeblob.c d12ed95dac0992e1e372d079d76af047cc42f7c7
 F src/vdbefifo.c 334c838c8f42d61a94813d136019ee566b5dc2f6
 F src/vdbemem.c 896fa3f8df9d2661eb15c7ce361857741b447268
@@ -403,7 +403,7 @@ F test/server1.test e328b8e641ba8fe9273132cfef497383185dc1f5
 F test/shared.test 08b30d5f1939efff0517e7ff8ec7b74ad31c151b
 F test/shared2.test 0ee9de8964d70e451936a48c41cb161d9134ccf4
 F test/shared3.test 01e3e124dbb3859788aabc7cfb82f7ea04421749
-F test/shared_err.test 99d3d87924cedc1db2233ef59f38c389dd358698
+F test/shared_err.test 494a24f6ba5994d4e4e8fe57ce8c6253e545409a
 F test/soak.test 64f9b27fbcdec43335a88c546ce1983e6ba40d7b
 F test/softheap1.test 0c49aa6eee25e7d32943e85e8d1f20eff566b1dc
 F test/sort.test 0e4456e729e5a92a625907c63dcdedfbe72c5dc5
@@ -567,7 +567,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 6c617bd89fc57881a2a308a6360e8ebb42835d46
-R 45b11caba5c119849cdae69b051cb491
+P 967ab229af462a8ae663090ea36b4cc10e351653
+R 9c42e7c4d50fc0b5627cd0c4b7aa2569
 U drh
-Z 8c8847e04e8b6bae7d208c08aa3c66c5
+Z b0b14ea00679504633b7555caa0627b8
diff --git a/manifest.uuid b/manifest.uuid
index 849256d4cf..f1c985484c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-967ab229af462a8ae663090ea36b4cc10e351653
\ No newline at end of file
+f84550be0a0c9e5859b852863b9a8f8ed3fd6919
\ No newline at end of file
diff --git a/src/btmutex.c b/src/btmutex.c
index 3b4d273718..f0f64c5704 100644
--- a/src/btmutex.c
+++ b/src/btmutex.c
@@ -10,7 +10,7 @@
 **
 *************************************************************************
 **
-** $Id: btmutex.c,v 1.2 2007/08/28 16:44:20 drh Exp $
+** $Id: btmutex.c,v 1.3 2007/08/28 23:28:08 drh Exp $
 **
 ** This file contains code used to implement mutexes on Btree objects.
 ** This code really belongs in btree.c.  But btree.c is getting too
@@ -110,7 +110,7 @@ void sqlite3BtreeLeave(Btree *p){
 }
 
 /*
-** Potentially dd a new Btree pointer to a BtreeMutexSet.
+** Potentially dd a new Btree pointer to a BtreeMutexArray.
 ** Really only add the Btree if it can possibly be shared with
 ** another database connection.
 **
@@ -122,7 +122,7 @@ void sqlite3BtreeLeave(Btree *p){
 ** The number of shared btrees will always be small (usually 0 or 1)
 ** so an insertion sort is an adequate algorithm here.
 */
-void sqlite3BtreeMutexSetInsert(BtreeMutexSet *pSet, Btree *pBtree){
+void sqlite3BtreeMutexArrayInsert(BtreeMutexArray *pSet, Btree *pBtree){
   int i, j;
   BtShared *pBt;
   if( !pBtree->sharable ) return;
@@ -150,11 +150,11 @@ void sqlite3BtreeMutexSetInsert(BtreeMutexSet *pSet, Btree *pBtree){
 }
 
 /*
-** Enter the mutex of every btree in the set.  This routine is
+** Enter the mutex of every btree in the array.  This routine is
 ** called at the beginning of sqlite3VdbeExec().  The mutexes are
 ** exited at the end of the same function.
 */
-void sqlite3BtreeMutexSetEnter(BtreeMutexSet *pSet){
+void sqlite3BtreeMutexArrayEnter(BtreeMutexArray *pSet){
   int i;
   for(i=0; i<pSet->nMutex; i++){
     Btree *p = pSet->aBtree[i];
@@ -175,9 +175,9 @@ void sqlite3BtreeMutexSetEnter(BtreeMutexSet *pSet){
 }
 
 /*
-** Leave the mutex of every btree in the set.
+** Leave the mutex of every btree in the group.
 */
-void sqlite3BtreeMutexSetLeave(BtreeMutexSet *pSet){
+void sqlite3BtreeMutexArrayLeave(BtreeMutexArray *pSet){
   int i;
   for(i=0; i<pSet->nMutex; i++){
     Btree *p = pSet->aBtree[i];
diff --git a/src/btree.c b/src/btree.c
index af8edac35d..800ea0508f 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 1.414 2007/08/28 22:24:35 drh Exp $
+** $Id: btree.c,v 1.415 2007/08/28 23:28:08 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -2420,7 +2420,10 @@ int sqlite3BtreeRollback(Btree *p){
     while( pBt->pCursor ){
       sqlite3 *db = pBt->pCursor->pBtree->pSqlite;
       if( db ){
+        /**** FIX ME: This can deadlock ****/
+        sqlite3_mutex_enter(db->mutex);
         sqlite3AbortOtherActiveVdbes(db, 0);
+        sqlite3_mutex_leave(db->mutex);
       }
     }
   }
diff --git a/src/btree.h b/src/btree.h
index 2af90f7713..c21b01074b 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -13,7 +13,7 @@
 ** subsystem.  See comments in the source code for a detailed description
 ** of what each interface routine does.
 **
-** @(#) $Id: btree.h,v 1.87 2007/08/28 02:27:52 drh Exp $
+** @(#) $Id: btree.h,v 1.88 2007/08/28 23:28:08 drh Exp $
 */
 #ifndef _BTREE_H_
 #define _BTREE_H_
@@ -41,7 +41,7 @@
 typedef struct Btree Btree;
 typedef struct BtCursor BtCursor;
 typedef struct BtShared BtShared;
-typedef struct BtreeMutexSet BtreeMutexSet;
+typedef struct BtreeMutexArray BtreeMutexArray;
 
 /*
 ** This structure records all of the Btrees that need to hold
@@ -49,7 +49,7 @@ typedef struct BtreeMutexSet BtreeMutexSet;
 ** are placed in aBtree[] in order of aBtree[]->pBt.  That way,
 ** we can always lock and unlock them all quickly.
 */
-struct BtreeMutexSet {
+struct BtreeMutexArray {
   int nMutex;
   Btree *aBtree[SQLITE_MAX_ATTACHED+1];
 };
@@ -183,13 +183,13 @@ int sqlite3BtreePageDump(Btree*, int, int recursive);
 #endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE
-  void sqlite3BtreeMutexSetEnter(BtreeMutexSet*);
-  void sqlite3BtreeMutexSetLeave(BtreeMutexSet*);
-  void sqlite3BtreeMutexSetInsert(BtreeMutexSet*, Btree*);
+  void sqlite3BtreeMutexArrayEnter(BtreeMutexArray*);
+  void sqlite3BtreeMutexArrayLeave(BtreeMutexArray*);
+  void sqlite3BtreeMutexArrayInsert(BtreeMutexArray*, Btree*);
 #else
-# define sqlite3BtreeMutexSetEnter(X)
-# define sqlite3BtreeMutexSetLeave(X)
-# define sqlite3BtreeMutexSetInsert(X,Y)
+# define sqlite3BtreeMutexArrayEnter(X)
+# define sqlite3BtreeMutexArrayLeave(X)
+# define sqlite3BtreeMutexArrayInsert(X,Y)
 #endif
 
 
diff --git a/src/vdbe.c b/src/vdbe.c
index 4519fc032b..9f9e240447 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 1.645 2007/08/28 02:27:52 drh Exp $
+** $Id: vdbe.c,v 1.646 2007/08/28 23:28:08 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -465,7 +465,7 @@ int sqlite3VdbeExec(
   if( p->magic!=VDBE_MAGIC_RUN ) return SQLITE_MISUSE;
   assert( db->magic==SQLITE_MAGIC_BUSY );
   pTos = p->pTos;
-  sqlite3BtreeMutexSetEnter(&p->mtxSet);
+  sqlite3BtreeMutexArrayEnter(&p->aMutex);
   if( p->rc==SQLITE_NOMEM ){
     /* This happens if a malloc() inside a call to sqlite3_column_text() or
     ** sqlite3_column_text16() failed.  */
@@ -5202,7 +5202,7 @@ vdbe_halt:
   ** release the mutexes on btrees that were acquired at the
   ** top. */
 vdbe_return:
-  sqlite3BtreeMutexSetLeave(&p->mtxSet);
+  sqlite3BtreeMutexArrayLeave(&p->aMutex);
   return rc;
 
   /* Jump to here if a string or blob larger than SQLITE_MAX_LENGTH
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index dc1b4b00d9..a807bdda33 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -333,7 +333,7 @@ struct Vdbe {
   int nChange;            /* Number of db changes made since last reset */
   i64 startTime;          /* Time when query started - used for profiling */
   int btreeMask;          /* Bitmask of db->aDb[] entries referenced */
-  BtreeMutexSet mtxSet;   /* Set of Btree mutexes */
+  BtreeMutexArray aMutex; /* An array of Btree used here and needing locks */
   int nSql;             /* Number of bytes in zSql */
   char *zSql;           /* Text of the SQL statement that generated this */
 #ifdef SQLITE_DEBUG
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 53a43255e9..5b58588a69 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -667,7 +667,7 @@ void sqlite3VdbeUsesBtree(Vdbe *p, int i, Btree *pBtree){
   assert( i<sizeof(p->btreeMask)*8 );
   assert( p->db->aDb[i].pBt==pBtree );
   p->btreeMask |= 1<<i;
-  sqlite3BtreeMutexSetInsert(&p->mtxSet, pBtree);
+  sqlite3BtreeMutexArrayInsert(&p->aMutex, pBtree);
 }
 
 
@@ -1331,7 +1331,7 @@ void sqlite3AbortOtherActiveVdbes(sqlite3 *db, Vdbe *pExcept){
 ** lock contention, return SQLITE_BUSY.  If SQLITE_BUSY is returned, it
 ** means the close did not happen and needs to be repeated.
 */
-int sqlite3VdbeHalt(Vdbe *p){
+static int sqlite3VdbeHaltLocked(Vdbe *p){
   sqlite3 *db = p->db;
   int i;
   int (*xFunc)(Btree *pBt) = 0;  /* Function to call on each btree backend */
@@ -1533,6 +1533,14 @@ int sqlite3VdbeHalt(Vdbe *p){
 
   return SQLITE_OK;
 }
+int sqlite3VdbeHalt(Vdbe *p){
+  int rc;
+  sqlite3BtreeMutexArrayEnter(&p->aMutex);
+  rc = sqlite3VdbeHaltLocked(p);
+  sqlite3BtreeMutexArrayLeave(&p->aMutex);
+  return rc;
+}
+
 
 /*
 ** Each VDBE holds the result of the most recent sqlite3_step() call
diff --git a/test/shared_err.test b/test/shared_err.test
index 11cef5a4c5..0496cd37d5 100644
--- a/test/shared_err.test
+++ b/test/shared_err.test
@@ -13,7 +13,7 @@
 # cache context. What happens to connection B if one connection A encounters
 # an IO-error whilst reading or writing the file-system?
 #
-# $Id: shared_err.test,v 1.13 2007/08/28 22:24:35 drh Exp $
+# $Id: shared_err.test,v 1.14 2007/08/28 23:28:09 drh Exp $
 
 proc skip {args} {}
 
@@ -156,7 +156,6 @@ do_ioerr_test shared_ioerr-3 -tclprep {
   sqlite3_step $::STMT       ;# Cursor points at 001.001.001.001
 
 } -tclbody {
-btree_breakpoint
   execsql {
     BEGIN;
     INSERT INTO t1 VALUES('201.201.201.201.201', NULL);