Index: src/select.c
==================================================================
--- src/select.c
+++ src/select.c
@@ -5332,18 +5332,21 @@
 
     /* Make copies of constant WHERE-clause terms in the outer query down
     ** inside the subquery.  This can help the subquery to run more efficiently.
     */
     if( (pItem->fg.jointype & JT_OUTER)==0
+     && OptimizationEnabled(db, SQLITE_PushDown)
      && pushDownWhereTerms(pParse, pSub, p->pWhere, pItem->iCursor)
     ){
 #if SELECTTRACE_ENABLED
       if( sqlite3SelectTrace & 0x100 ){
         SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
         sqlite3TreeViewSelect(0, p, 0);
       }
 #endif
+    }else{
+      SELECTTRACE(0x100,pParse,p,("Push-down not possible\n"));
     }
 
     zSavedAuthContext = pParse->zAuthContext;
     pParse->zAuthContext = pItem->zName;
 

Index: src/shell.c.in
==================================================================
--- src/shell.c.in
+++ src/shell.c.in
@@ -2877,11 +2877,16 @@
             explain_data_delete(pArg);
           }
           sqlite3_finalize(pExplain);
           sqlite3_free(zEQP);
         }
-        sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, triggerEQP, 0);
+        if( pArg->autoEQP>=AUTOEQP_trigger && triggerEQP==0 ){
+          sqlite3_db_config(db, SQLITE_DBCONFIG_TRIGGER_EQP, 0, 0);
+          /* Reprepare pStmt before reactiving trace modes */
+          sqlite3_finalize(pStmt);
+          sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+        }
         restore_debug_trace_modes();
       }
 
       if( pArg ){
         pArg->cMode = pArg->mode;

Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -2052,31 +2052,40 @@
 ** <dd> Usually, when a database in wal mode is closed or detached from a 
 ** database handle, SQLite checks if this will mean that there are now no 
 ** connections at all to the database. If so, it performs a checkpoint 
 ** operation before closing the connection. This option may be used to
 ** override this behaviour. The first parameter passed to this operation
-** is an integer - non-zero to disable checkpoints-on-close, or zero (the
-** default) to enable them. The second parameter is a pointer to an integer
+** is an integer - positive to disable checkpoints-on-close, or zero (the
+** default) to enable them, and negative to leave the setting unchanged.
+** The second parameter is a pointer to an integer
 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
 ** have been disabled - 0 if they are not disabled, 1 if they are.
 ** </dd>
+**
 ** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
 ** the [query planner stability guarantee] (QPSG).  When the QPSG is active,
 ** a single SQL query statement will always use the same algorithm regardless
 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
 ** that look at the values of bound parameters, which can make some queries
 ** slower.  But the QPSG has the advantage of more predictable behavior.  With
 ** the QPSG active, SQLite will always use the same query plan in the field as
 ** was used during testing in the lab.
+** The first argument to this setting is an integer which is 0 to disable 
+** the QPSG, positive to enable QPSG, or negative to leave the setting
+** unchanged. The second parameter is a pointer to an integer into which
+** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
+** following this call.
 ** </dd>
+**
 ** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 
 ** include output for any operations performed by trigger programs. This
 ** option is used to set or clear (the default) a flag that governs this
 ** behavior. The first parameter passed to this operation is an integer -
-** non-zero to enable output for trigger programs, or zero to disable it.
+** positive to enable output for trigger programs, or zero to disable it,
+** or negative to leave the setting unchanged.
 ** The second parameter is a pointer to an integer into which is written 
 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 
 ** it is not disabled, 1 if it is.  
 ** </dd>
 ** </dl>

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -1530,10 +1530,11 @@
 #define SQLITE_OmitNoopJoin   0x0100   /* Omit unused tables in joins */
 #define SQLITE_CountOfView    0x0200   /* The count-of-view optimization */
 #define SQLITE_CursorHints    0x0400   /* Add OP_CursorHint opcodes */
 #define SQLITE_Stat34         0x0800   /* Use STAT3 or STAT4 data */
    /* TH3 expects the Stat34  ^^^^^^ value to be 0x0800.  Don't change it */
+#define SQLITE_PushDown       0x1000   /* The push-down optimization */
 #define SQLITE_AllOpts        0xffff   /* All optimizations */
 
 /*
 ** Macros for testing whether or not optimizations are enabled or disabled.
 */