Merge all trunk changes since 3.8.1 into the sessions branch.

FossilOrigin-Name: aa72ea8a004de7fe744fc13baef19d05aea607d5

7 files changed, 178 insertions, 45 deletions

diff --git a/src/build.c b/src/build.c
index 6868e60e0..38bdad859 100644
--- a/src/build.c
+++ b/src/build.c
@@ -1714,7 +1714,7 @@ void sqlite3EndTable(
 
     /* Reparse everything to update our internal data structures */
     sqlite3VdbeAddParseSchemaOp(v, iDb,
-               sqlite3MPrintf(db, "tbl_name='%q'", p->zName));
+           sqlite3MPrintf(db, "tbl_name='%q' AND type!='trigger'", p->zName));
   }
 
 
diff --git a/src/pragma.c b/src/pragma.c
index a1f32c36d..b130ba461 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -94,12 +94,14 @@ static const struct sPragmaNames {
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_AUTOMATIC_INDEX)
   { /* zName:     */ "automatic_index",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_AutoIndex },
 #endif
+#endif
   { /* zName:     */ "busy_timeout",
     /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
     /* ePragFlag: */ 0,
@@ -110,18 +112,22 @@ static const struct sPragmaNames {
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "cache_spill",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_CacheSpill },
+#endif
   { /* zName:     */ "case_sensitive_like",
     /* ePragTyp:  */ PragTyp_CASE_SENSITIVE_LIKE,
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "checkpoint_fullfsync",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_CkptFullFSync },
+#endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
   { /* zName:     */ "collation_list",
     /* ePragTyp:  */ PragTyp_COLLATION_LIST,
@@ -134,10 +140,12 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "count_changes",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_CountRows },
+#endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_OS_WIN
   { /* zName:     */ "data_store_directory",
     /* ePragTyp:  */ PragTyp_DATA_STORE_DIRECTORY,
@@ -156,16 +164,20 @@ static const struct sPragmaNames {
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
   { /* zName:     */ "defer_foreign_keys",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_DeferFKs },
 #endif
+#endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "empty_result_callbacks",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_NullCallback },
+#endif
 #if !defined(SQLITE_OMIT_UTF16)
   { /* zName:     */ "encoding",
     /* ePragTyp:  */ PragTyp_ENCODING,
@@ -184,18 +196,21 @@ static const struct sPragmaNames {
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
   { /* zName:     */ "foreign_keys",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_ForeignKeys },
 #endif
+#endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
   { /* zName:     */ "freelist_count",
     /* ePragTyp:  */ PragTyp_HEADER_VALUE,
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "full_column_names",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
@@ -204,6 +219,7 @@ static const struct sPragmaNames {
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_FullFSync },
+#endif
 #if defined(SQLITE_HAS_CODEC)
   { /* zName:     */ "hexkey",
     /* ePragTyp:  */ PragTyp_HEXKEY,
@@ -214,12 +230,14 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if !defined(SQLITE_OMIT_CHECK)
   { /* zName:     */ "ignore_check_constraints",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_IgnoreChecks },
 #endif
+#endif
 #if !defined(SQLITE_OMIT_AUTOVACUUM)
   { /* zName:     */ "incremental_vacuum",
     /* ePragTyp:  */ PragTyp_INCREMENTAL_VACUUM,
@@ -258,10 +276,12 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "legacy_file_format",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_LegacyFileFmt },
+#endif
 #if !defined(SQLITE_OMIT_PAGER_PRAGMAS) && SQLITE_ENABLE_LOCKING_STYLE
   { /* zName:     */ "lock_proxy_file",
     /* ePragTyp:  */ PragTyp_LOCK_PROXY_FILE,
@@ -302,16 +322,19 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "query_only",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_QueryOnly },
+#endif
 #if !defined(SQLITE_OMIT_INTEGRITY_CHECK)
   { /* zName:     */ "quick_check",
     /* ePragTyp:  */ PragTyp_INTEGRITY_CHECK,
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "read_uncommitted",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
@@ -320,16 +343,19 @@ static const struct sPragmaNames {
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_RecTriggers },
+#endif
 #if defined(SQLITE_HAS_CODEC)
   { /* zName:     */ "rekey",
     /* ePragTyp:  */ PragTyp_REKEY,
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "reverse_unordered_selects",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_ReverseOrder },
+#endif
 #if !defined(SQLITE_OMIT_SCHEMA_VERSION_PRAGMAS)
   { /* zName:     */ "schema_version",
     /* ePragTyp:  */ PragTyp_HEADER_VALUE,
@@ -342,10 +368,12 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "short_column_names",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_ShortColNames },
+#endif
   { /* zName:     */ "shrink_memory",
     /* ePragTyp:  */ PragTyp_SHRINK_MEMORY,
     /* ePragFlag: */ 0,
@@ -354,12 +382,14 @@ static const struct sPragmaNames {
     /* ePragTyp:  */ PragTyp_SOFT_HEAP_LIMIT,
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if defined(SQLITE_DEBUG)
   { /* zName:     */ "sql_trace",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_SqlTrace },
 #endif
+#endif
 #if !defined(SQLITE_OMIT_SCHEMA_PRAGMAS)
   { /* zName:     */ "stats",
     /* ePragTyp:  */ PragTyp_STATS,
@@ -394,6 +424,7 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
 #if defined(SQLITE_DEBUG)
   { /* zName:     */ "vdbe_addoptrace",
     /* ePragTyp:  */ PragTyp_FLAG,
@@ -412,6 +443,7 @@ static const struct sPragmaNames {
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_VdbeTrace },
 #endif
+#endif
 #if !defined(SQLITE_OMIT_WAL)
   { /* zName:     */ "wal_autocheckpoint",
     /* ePragTyp:  */ PragTyp_WAL_AUTOCHECKPOINT,
@@ -422,10 +454,12 @@ static const struct sPragmaNames {
     /* ePragFlag: */ PragFlag_NeedSchema,
     /* iArg:      */ 0 },
 #endif
+#if !defined(SQLITE_OMIT_FLAG_PRAGMAS)
   { /* zName:     */ "writable_schema",
     /* ePragTyp:  */ PragTyp_FLAG,
     /* ePragFlag: */ 0,
     /* iArg:      */ SQLITE_WriteSchema|SQLITE_RecoveryMode },
+#endif
 };
 /* Number of pragmas: 56 on by default, 68 total. */
 /* End of the automatically generated pragma table.
diff --git a/src/resolve.c b/src/resolve.c
index dfe4b84c4..92fbaaf15 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -709,7 +709,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
           }else{
             /* EVIDENCE-OF: R-61304-29449 The unlikely(X) function is equivalent to
             ** likelihood(X, 0.0625).
-            ** EVIDENCE-OF: R-35738-39582 The unlikely(X) fucntion is short-hand for
+            ** EVIDENCE-OF: R-01283-11636 The unlikely(X) function is short-hand for
             ** likelihood(X,0.0625). */
             pExpr->iTable = 62;  /* TUNING:  Default 2nd arg to unlikely() is 0.0625 */
           }             
diff --git a/src/shell.c b/src/shell.c
index 41ea56492..26c38c59e 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -436,6 +436,7 @@ struct callback_data {
                          ** .explain ON */
   char outfile[FILENAME_MAX]; /* Filename for *out */
   const char *zDbFilename;    /* name of the database file */
+  char *zFreeOnClose;         /* Filename to free when closing */
   const char *zVfs;           /* Name of VFS to use */
   sqlite3_stmt *pStmt;   /* Current statement if any. */
   FILE *pLog;            /* Write log output here */
@@ -1437,6 +1438,7 @@ static char zHelp[] =
   "                         tabs     Tab-separated values\n"
   "                         tcl      TCL list elements\n"
   ".nullvalue STRING      Use STRING in place of NULL values\n"
+  ".open ?FILENAME?       Close existing database and reopen FILENAME\n"
   ".output FILENAME       Send output to FILENAME\n"
   ".output stdout         Send output to the screen\n"
   ".print STRING...       Print literal STRING\n"
@@ -1470,7 +1472,7 @@ static int process_input(struct callback_data *p, FILE *in);
 ** Make sure the database is open.  If it is not, then open it.  If
 ** the database fails to open, print an error message and exit.
 */
-static void open_db(struct callback_data *p){
+static void open_db(struct callback_data *p, int keepAlive){
   if( p->db==0 ){
     sqlite3_initialize();
     sqlite3_open(p->zDbFilename, &p->db);
@@ -1482,6 +1484,7 @@ static void open_db(struct callback_data *p){
     if( db==0 || SQLITE_OK!=sqlite3_errcode(db) ){
       fprintf(stderr,"Error: unable to open database \"%s\": %s\n", 
           p->zDbFilename, sqlite3_errmsg(db));
+      if( keepAlive ) return;
       exit(1);
     }
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
@@ -1834,7 +1837,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
       sqlite3_close(pDest);
       return 1;
     }
-    open_db(p);
+    open_db(p, 0);
     pBackup = sqlite3_backup_init(pDest, "main", p->db, zDb);
     if( pBackup==0 ){
       fprintf(stderr, "Error: %s\n", sqlite3_errmsg(pDest));
@@ -1866,7 +1869,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   if( c=='d' && n>1 && strncmp(azArg[0], "databases", n)==0 && nArg==1 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 1;
     data.mode = MODE_Column;
@@ -1883,7 +1886,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   }else
 
   if( c=='d' && strncmp(azArg[0], "dump", n)==0 && nArg<3 ){
-    open_db(p);
+    open_db(p, 0);
     /* When playing back a "dump", the content might appear in an order
     ** which causes immediate foreign key constraints to be violated.
     ** So disable foreign-key constraint enforcement to prevent problems. */
@@ -2002,7 +2005,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
 
     seenInterrupt = 0;
     memset(&sCsv, 0, sizeof(sCsv));
-    open_db(p);
+    open_db(p, 0);
     nSep = strlen30(p->separator);
     if( nSep==0 ){
       fprintf(stderr, "Error: non-null separator required for import\n");
@@ -2140,7 +2143,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   if( c=='i' && strncmp(azArg[0], "indices", n)==0 && nArg<3 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 0;
     data.mode = MODE_List;
@@ -2206,7 +2209,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
     char *zErrMsg = 0;
     zFile = azArg[1];
     zProc = nArg>=3 ? azArg[2] : 0;
-    open_db(p);
+    open_db(p, 0);
     rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
     if( rc!=SQLITE_OK ){
       fprintf(stderr, "Error: %s\n", zErrMsg);
@@ -2272,6 +2275,26 @@ static int do_meta_command(char *zLine, struct callback_data *p){
                      "%.*s", (int)ArraySize(p->nullvalue)-1, azArg[1]);
   }else
 
+  if( c=='o' && strncmp(azArg[0], "open", n)==0 && n>=2 ){
+    sqlite3 *savedDb = p->db;
+    const char *zSavedFilename = p->zDbFilename;
+    char *zNewFilename = 0;
+    p->db = 0;
+    if( nArg>=2 ){
+      p->zDbFilename = zNewFilename = sqlite3_mprintf("%s", azArg[1]);
+    }
+    open_db(p, 1);
+    if( p->db!=0 ){
+      sqlite3_close(savedDb);
+      sqlite3_free(p->zFreeOnClose);
+      p->zFreeOnClose = zNewFilename;
+    }else{
+      sqlite3_free(zNewFilename);
+      p->db = savedDb;
+      p->zDbFilename = zSavedFilename;
+    }
+  }else
+
   if( c=='o' && strncmp(azArg[0], "output", n)==0 && nArg==2 ){
     if( p->outfile[0]=='|' ){
       pclose(p->out);
@@ -2355,7 +2378,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
       sqlite3_close(pSrc);
       return 1;
     }
-    open_db(p);
+    open_db(p, 0);
     pBackup = sqlite3_backup_init(p->db, zDb, pSrc, "main");
     if( pBackup==0 ){
       fprintf(stderr, "Error: %s\n", sqlite3_errmsg(p->db));
@@ -2385,7 +2408,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   if( c=='s' && strncmp(azArg[0], "schema", n)==0 && nArg<3 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 0;
     data.mode = MODE_Semi;
@@ -2516,7 +2539,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
     int nRow, nAlloc;
     char *zSql = 0;
     int ii;
-    open_db(p);
+    open_db(p, 0);
     rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
     if( rc ) return rc;
     zSql = sqlite3_mprintf(
@@ -2616,7 +2639,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
     int testctrl = -1;
     int rc = 0;
     int i, n;
-    open_db(p);
+    open_db(p, 0);
 
     /* convert testctrl text option to value. allow any unique prefix
     ** of the option name, or a numerical value. */
@@ -2715,7 +2738,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   }else
 
   if( c=='t' && n>4 && strncmp(azArg[0], "timeout", n)==0 && nArg==2 ){
-    open_db(p);
+    open_db(p, 0);
     sqlite3_busy_timeout(p->db, (int)integerValue(azArg[1]));
   }else
     
@@ -2726,7 +2749,7 @@ static int do_meta_command(char *zLine, struct callback_data *p){
   }else
   
   if( c=='t' && strncmp(azArg[0], "trace", n)==0 && nArg>1 ){
-    open_db(p);
+    open_db(p, 0);
     output_file_close(p->traceOut);
     p->traceOut = output_file_open(azArg[1]);
 #if !defined(SQLITE_OMIT_TRACE) && !defined(SQLITE_OMIT_FLOATING_POINT)
@@ -2918,7 +2941,7 @@ static int process_input(struct callback_data *p, FILE *in){
     if( nSql && line_contains_semicolon(&zSql[nSqlPrior], nSql-nSqlPrior)
                 && sqlite3_complete(zSql) ){
       p->cnt = 0;
-      open_db(p);
+      open_db(p, 0);
       BEGIN_TIMER;
       rc = shell_exec(p->db, zSql, shell_callback, p, &zErrMsg);
       END_TIMER;
@@ -3245,7 +3268,7 @@ int main(int argc, char **argv){
   ** to the sqlite command-line tool.
   */
   if( access(data.zDbFilename, 0)==0 ){
-    open_db(&data);
+    open_db(&data, 0);
   }
 
   /* Process the initialization file if there is one.  If no -init option
@@ -3325,7 +3348,7 @@ int main(int argc, char **argv){
         rc = do_meta_command(z, &data);
         if( rc && bail_on_error ) return rc==2 ? 0 : rc;
       }else{
-        open_db(&data);
+        open_db(&data, 0);
         rc = shell_exec(data.db, z, shell_callback, &data, &zErrMsg);
         if( zErrMsg!=0 ){
           fprintf(stderr,"Error: %s\n", zErrMsg);
@@ -3349,7 +3372,7 @@ int main(int argc, char **argv){
       rc = do_meta_command(zFirstCmd, &data);
       if( rc==2 ) rc = 0;
     }else{
-      open_db(&data);
+      open_db(&data, 0);
       rc = shell_exec(data.db, zFirstCmd, shell_callback, &data, &zErrMsg);
       if( zErrMsg!=0 ){
         fprintf(stderr,"Error: %s\n", zErrMsg);
@@ -3396,5 +3419,6 @@ int main(int argc, char **argv){
   if( data.db ){
     sqlite3_close(data.db);
   }
+  sqlite3_free(data.zFreeOnClose); 
   return rc;
 }
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 461b09ad3..8b1c14bf8 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -907,6 +907,14 @@ struct sqlite3_io_methods {
 ** can be queried by passing in a pointer to a negative number.  This
 ** file-control is used internally to implement [PRAGMA mmap_size].
 **
+** <li>[[SQLITE_FCNTL_TRACE]]
+** The [SQLITE_FCNTL_TRACE] file control provides advisory information
+** to the VFS about what the higher layers of the SQLite stack are doing.
+** This file control is used by some VFS activity tracing [shims].
+** The argument is a zero-terminated string.  Higher layers in the
+** SQLite stack may generate instances of this file control if
+** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
+**
 ** </ul>
 */
 #define SQLITE_FCNTL_LOCKSTATE               1
@@ -926,6 +934,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_BUSYHANDLER            15
 #define SQLITE_FCNTL_TEMPFILENAME           16
 #define SQLITE_FCNTL_MMAP_SIZE              18
+#define SQLITE_FCNTL_TRACE                  19
 
 /*
 ** CAPI3REF: Mutex Handle
diff --git a/src/vdbe.c b/src/vdbe.c
index 95e8c6e57..9b384b4c6 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -6190,6 +6190,16 @@ case OP_Trace: {
     db->xTrace(db->pTraceArg, z);
     sqlite3DbFree(db, z);
   }
+#ifdef SQLITE_USE_FCNTL_TRACE
+  zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
+  if( zTrace ){
+    int i;
+    for(i=0; i<db->nDb; i++){
+      if( ((1<<i) & p->btreeMask)==0 ) continue;
+      sqlite3_file_control(db, db->aDb[i].zName, SQLITE_FCNTL_TRACE, zTrace);
+    }
+  }
+#endif /* SQLITE_USE_FCNTL_TRACE */
 #ifdef SQLITE_DEBUG
   if( (db->flags & SQLITE_SqlTrace)!=0
    && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
diff --git a/src/where.c b/src/where.c
index d89ce6513..304732db6 100644
--- a/src/where.c
+++ b/src/where.c
@@ -878,7 +878,10 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
     iColumn = pScan->aEquiv[pScan->iEquiv-1];
     while( (pWC = pScan->pWC)!=0 ){
       for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
-        if( pTerm->leftCursor==iCur && pTerm->u.leftColumn==iColumn ){
+        if( pTerm->leftCursor==iCur
+         && pTerm->u.leftColumn==iColumn
+         && (pScan->iEquiv<=2 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+        ){
           if( (pTerm->eOperator & WO_EQUIV)!=0
            && pScan->nEquiv<ArraySize(pScan->aEquiv)
           ){
@@ -2550,7 +2553,7 @@ static int whereRangeScanEst(
         nOut = nNew;
       }
       pLoop->nOut = (LogEst)nOut;
-      WHERETRACE(0x100, ("range scan regions: %u..%u  est=%d\n",
+      WHERETRACE(0x10, ("range scan regions: %u..%u  est=%d\n",
                          (u32)iLower, (u32)iUpper, nOut));
       return SQLITE_OK;
     }
@@ -2636,7 +2639,7 @@ static int whereEqualScanEst(
   pBuilder->nRecValid = nEq;
 
   whereKeyStats(pParse, p, pRec, 0, a);
-  WHERETRACE(0x100,("equality scan regions: %d\n", (int)a[1]));
+  WHERETRACE(0x10,("equality scan regions: %d\n", (int)a[1]));
   *pnRow = a[1];
   
   return rc;
@@ -2684,7 +2687,7 @@ static int whereInScanEst(
   if( rc==SQLITE_OK ){
     if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
     *pnRow = nRowEst;
-    WHERETRACE(0x100,("IN row estimate: est=%g\n", nRowEst));
+    WHERETRACE(0x10,("IN row estimate: est=%g\n", nRowEst));
   }
   assert( pBuilder->nRecValid==nRecValid );
   return rc;
@@ -3889,22 +3892,38 @@ static Bitmask codeOneLoopStart(
   return pLevel->notReady;
 }
 
+#if defined(WHERETRACE_ENABLED) && defined(SQLITE_ENABLE_TREE_EXPLAIN)
+/*
+** Generate "Explanation" text for a WhereTerm.
+*/
+static void whereExplainTerm(Vdbe *v, WhereTerm *pTerm){
+  char zType[4];
+  memcpy(zType, "...", 4);
+  if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V';
+  if( pTerm->eOperator & WO_EQUIV  ) zType[1] = 'E';
+  if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L';
+  sqlite3ExplainPrintf(v, "%s ", zType);
+  sqlite3ExplainExpr(v, pTerm->pExpr);
+}
+#endif /* WHERETRACE_ENABLED && SQLITE_ENABLE_TREE_EXPLAIN */
+
+
 #ifdef WHERETRACE_ENABLED
 /*
 ** Print a WhereLoop object for debugging purposes
 */
-static void whereLoopPrint(WhereLoop *p, SrcList *pTabList){
-  int nb = 1+(pTabList->nSrc+7)/8;
-  struct SrcList_item *pItem = pTabList->a + p->iTab;
+static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){
+  WhereInfo *pWInfo = pWC->pWInfo;
+  int nb = 1+(pWInfo->pTabList->nSrc+7)/8;
+  struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab;
   Table *pTab = pItem->pTab;
   sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
                      p->iTab, nb, p->maskSelf, nb, p->prereq);
   sqlite3DebugPrintf(" %12s",
                      pItem->zAlias ? pItem->zAlias : pTab->zName);
   if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
-    if( p->u.btree.pIndex ){
-      const char *zName = p->u.btree.pIndex->zName;
-      if( zName==0 ) zName = "ipk";
+     const char *zName;
+     if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){
       if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
         int i = sqlite3Strlen30(zName) - 1;
         while( zName[i]!='_' ) i--;
@@ -3927,6 +3946,26 @@ static void whereLoopPrint(WhereLoop *p, SrcList *pTabList){
   }
   sqlite3DebugPrintf(" f %04x N %d", p->wsFlags, p->nLTerm);
   sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+#ifdef SQLITE_ENABLE_TREE_EXPLAIN
+  /* If the 0x100 bit of wheretracing is set, then show all of the constraint
+  ** expressions in the WhereLoop.aLTerm[] array.
+  */
+  if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){  /* WHERETRACE 0x100 */
+    int i;
+    Vdbe *v = pWInfo->pParse->pVdbe;
+    sqlite3ExplainBegin(v);
+    for(i=0; i<p->nLTerm; i++){
+      WhereTerm *pTerm = p->aLTerm[i];
+      sqlite3ExplainPrintf(v, "  (%d) #%-2d ", i+1, (int)(pTerm-pWC->a));
+      sqlite3ExplainPush(v);
+      whereExplainTerm(v, pTerm);
+      sqlite3ExplainPop(v);
+      sqlite3ExplainNL(v);
+    }
+    sqlite3ExplainFinish(v);
+    sqlite3DebugPrintf("%s", sqlite3VdbeExplanation(v));
+  }
+#endif
 }
 #endif
 
@@ -4066,10 +4105,10 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
 #endif
     whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
                                     pTemplate->nOut);
-#if WHERETRACE_ENABLED
+#if WHERETRACE_ENABLED /* 0x8 */
     if( sqlite3WhereTrace & 0x8 ){
       sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
-      whereLoopPrint(pTemplate, pWInfo->pTabList);
+      whereLoopPrint(pTemplate, pBuilder->pWC);
     }
 #endif
     return SQLITE_OK;
@@ -4139,14 +4178,14 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
   ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
   ** WhereLoop and insert it.
   */
-#if WHERETRACE_ENABLED
+#if WHERETRACE_ENABLED /* 0x8 */
   if( sqlite3WhereTrace & 0x8 ){
     if( p!=0 ){
       sqlite3DebugPrintf("ins-del:  ");
-      whereLoopPrint(p, pWInfo->pTabList);
+      whereLoopPrint(p, pBuilder->pWC);
     }
     sqlite3DebugPrintf("ins-new:  ");
-    whereLoopPrint(pTemplate, pWInfo->pTabList);
+    whereLoopPrint(pTemplate, pBuilder->pWC);
   }
 #endif
   if( p==0 ){
@@ -4167,10 +4206,10 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
 
   /* Jump here if the insert is a no-op */
 whereLoopInsert_noop:
-#if WHERETRACE_ENABLED
+#if WHERETRACE_ENABLED /* 0x8 */
   if( sqlite3WhereTrace & 0x8 ){
     sqlite3DebugPrintf("ins-noop: ");
-    whereLoopPrint(pTemplate, pWInfo->pTabList);
+    whereLoopPrint(pTemplate, pBuilder->pWC);
   }
 #endif
   return SQLITE_OK;  
@@ -5328,7 +5367,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
         }
         if( jj>=nTo ){
           if( nTo>=mxChoice && rCost>=mxCost ){
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
               sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
                   wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
@@ -5346,7 +5385,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
             jj = mxI;
           }
           pTo = &aTo[jj];
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
             sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
                 wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
@@ -5355,7 +5394,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
 #endif
         }else{
           if( pTo->rCost<=rCost && pTo->nRow<=nOut ){
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* 0x4 */
             if( sqlite3WhereTrace&0x4 ){
               sqlite3DebugPrintf(
                   "Skip   %s cost=%-3d,%3d order=%c",
@@ -5371,7 +5410,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
           }
           testcase( pTo->rCost==rCost+1 );
           /* A new and better score for a previously created equivalent path */
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* 0x4 */
           if( sqlite3WhereTrace&0x4 ){
             sqlite3DebugPrintf(
                 "Update %s cost=%-3d,%3d order=%c",
@@ -5407,7 +5446,7 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){
       }
     }
 
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED  /* >=2 */
     if( sqlite3WhereTrace>=2 ){
       sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
       for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
@@ -5816,12 +5855,29 @@ WhereInfo *sqlite3WhereBegin(
 
   /* Construct the WhereLoop objects */
   WHERETRACE(0xffff,("*** Optimizer Start ***\n"));
+  /* Display all terms of the WHERE clause */
+#if defined(WHERETRACE_ENABLED) && defined(SQLITE_ENABLE_TREE_EXPLAIN)
+  if( sqlite3WhereTrace & 0x100 ){
+    int i;
+    Vdbe *v = pParse->pVdbe;
+    sqlite3ExplainBegin(v);
+    for(i=0; i<sWLB.pWC->nTerm; i++){
+      sqlite3ExplainPrintf(v, "#%-2d ", i);
+      sqlite3ExplainPush(v);
+      whereExplainTerm(v, &sWLB.pWC->a[i]);
+      sqlite3ExplainPop(v);
+      sqlite3ExplainNL(v);
+    }
+    sqlite3ExplainFinish(v);
+    sqlite3DebugPrintf("%s", sqlite3VdbeExplanation(v));
+  }
+#endif
   if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
     rc = whereLoopAddAll(&sWLB);
     if( rc ) goto whereBeginError;
   
     /* Display all of the WhereLoop objects if wheretrace is enabled */
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* !=0 */
     if( sqlite3WhereTrace ){
       WhereLoop *p;
       int i;
@@ -5829,7 +5885,7 @@ WhereInfo *sqlite3WhereBegin(
                                        "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
       for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
         p->cId = zLabel[i%sizeof(zLabel)];
-        whereLoopPrint(p, pTabList);
+        whereLoopPrint(p, sWLB.pWC);
       }
     }
 #endif
@@ -5847,7 +5903,7 @@ WhereInfo *sqlite3WhereBegin(
   if( pParse->nErr || NEVER(db->mallocFailed) ){
     goto whereBeginError;
   }
-#ifdef WHERETRACE_ENABLED
+#ifdef WHERETRACE_ENABLED /* !=0 */
   if( sqlite3WhereTrace ){
     int ii;
     sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
@@ -5870,7 +5926,7 @@ WhereInfo *sqlite3WhereBegin(
     }
     sqlite3DebugPrintf("\n");
     for(ii=0; ii<pWInfo->nLevel; ii++){
-      whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
+      whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC);
     }
   }
 #endif