Index: src/fkey.c
==================================================================
--- src/fkey.c
+++ src/fkey.c
@@ -631,14 +631,16 @@
   sqlite3ResolveExprNames(&sNameContext, pWhere);
 
   /* Create VDBE to loop through the entries in pSrc that match the WHERE
   ** clause. For each row found, increment either the deferred or immediate
   ** foreign key constraint counter. */
-  pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
-  sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
-  if( pWInfo ){
-    sqlite3WhereEnd(pWInfo);
+  if( pParse->nErr==0 ){
+    pWInfo = sqlite3WhereBegin(pParse, pSrc, pWhere, 0, 0, 0, 0);
+    sqlite3VdbeAddOp2(v, OP_FkCounter, pFKey->isDeferred, nIncr);
+    if( pWInfo ){
+      sqlite3WhereEnd(pWInfo);
+    }
   }
 
   /* Clean up the WHERE clause constructed above. */
   sqlite3ExprDelete(db, pWhere);
   if( iFkIfZero ){

Index: src/tclsqlite.c
==================================================================
--- src/tclsqlite.c
+++ src/tclsqlite.c
@@ -159,10 +159,11 @@
   SqlPreparedStmt *stmtLast; /* Last statement in the list */
   int maxStmt;               /* The next maximum number of stmtList */
   int nStmt;                 /* Number of statements in stmtList */
   IncrblobChannel *pIncrblob;/* Linked list of open incrblob channels */
   int nStep, nSort, nIndex;  /* Statistics for most recent operation */
+  int nVMStep;               /* Another statistic for most recent operation */
   int nTransaction;          /* Number of nested [transaction] methods */
   int openFlags;             /* Flags used to open.  (SQLITE_OPEN_URI) */
 #ifdef SQLITE_TEST
   int bLegacyPrepare;        /* True to use sqlite3_prepare() */
 #endif
@@ -1586,10 +1587,11 @@
       rcs = sqlite3_reset(pStmt);
 
       pDb->nStep = sqlite3_stmt_status(pStmt,SQLITE_STMTSTATUS_FULLSCAN_STEP,1);
       pDb->nSort = sqlite3_stmt_status(pStmt,SQLITE_STMTSTATUS_SORT,1);
       pDb->nIndex = sqlite3_stmt_status(pStmt,SQLITE_STMTSTATUS_AUTOINDEX,1);
+      pDb->nVMStep = sqlite3_stmt_status(pStmt,SQLITE_STMTSTATUS_VM_STEP,1);
       dbReleaseColumnNames(p);
       p->pPreStmt = 0;
 
       if( rcs!=SQLITE_OK ){
         /* If a run-time error occurs, report the error and stop reading
@@ -2853,11 +2855,11 @@
     sqlite3_close(pSrc);
     break;
   }
 
   /*
-  **     $db status (step|sort|autoindex)
+  **     $db status (step|sort|autoindex|vmstep)
   **
   ** Display SQLITE_STMTSTATUS_FULLSCAN_STEP or
   ** SQLITE_STMTSTATUS_SORT for the most recent eval.
   */
   case DB_STATUS: {
@@ -2872,13 +2874,15 @@
       v = pDb->nStep;
     }else if( strcmp(zOp, "sort")==0 ){
       v = pDb->nSort;
     }else if( strcmp(zOp, "autoindex")==0 ){
       v = pDb->nIndex;
+    }else if( strcmp(zOp, "vmstep")==0 ){
+      v = pDb->nVMStep;
     }else{
       Tcl_AppendResult(interp,
-            "bad argument: should be autoindex, step, or sort",
+            "bad argument: should be autoindex, step, sort or vmstep",
             (char*)0);
       return TCL_ERROR;
     }
     Tcl_SetObjResult(interp, Tcl_NewIntObj(v));
     break;

Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -4291,10 +4291,35 @@
 #endif
     return 1;
   }
   return 0;
 }
+
+/*
+** Helper function for exprIsDeterministic().
+*/
+static int exprNodeIsDeterministic(Walker *pWalker, Expr *pExpr){
+  if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_ConstFunc)==0 ){
+    pWalker->eCode = 0;
+    return WRC_Abort;
+  }
+  return WRC_Continue;
+}
+
+/*
+** Return true if the expression contains no non-deterministic SQL 
+** functions. Do not consider non-deterministic SQL functions that are 
+** part of sub-select statements.
+*/
+static int exprIsDeterministic(Expr *p){
+  Walker w;
+  memset(&w, 0, sizeof(w));
+  w.eCode = 1;
+  w.xExprCallback = exprNodeIsDeterministic;
+  sqlite3WalkExpr(&w, p);
+  return w.eCode;
+}
 
 /*
 ** Generate the beginning of the loop used for WHERE clause processing.
 ** The return value is a pointer to an opaque structure that contains
 ** information needed to terminate the loop.  Later, the calling routine
@@ -4490,21 +4515,10 @@
   */
   initMaskSet(pMaskSet);
   sqlite3WhereClauseInit(&pWInfo->sWC, pWInfo);
   sqlite3WhereSplit(&pWInfo->sWC, pWhere, TK_AND);
     
-  /* Special case: a WHERE clause that is constant.  Evaluate the
-  ** expression and either jump over all of the code or fall thru.
-  */
-  for(ii=0; ii<sWLB.pWC->nTerm; ii++){
-    if( nTabList==0 || sqlite3ExprIsConstantNotJoin(sWLB.pWC->a[ii].pExpr) ){
-      sqlite3ExprIfFalse(pParse, sWLB.pWC->a[ii].pExpr, pWInfo->iBreak,
-                         SQLITE_JUMPIFNULL);
-      sWLB.pWC->a[ii].wtFlags |= TERM_CODED;
-    }
-  }
-
   /* Special case: No FROM clause
   */
   if( nTabList==0 ){
     if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr;
     if( wctrlFlags & WHERE_WANT_DISTINCT ){
@@ -4538,10 +4552,29 @@
 #endif
 
   /* Analyze all of the subexpressions. */
   sqlite3WhereExprAnalyze(pTabList, &pWInfo->sWC);
   if( db->mallocFailed ) goto whereBeginError;
+
+  /* Special case: WHERE terms that do not refer to any tables in the join
+  ** (constant expressions). Evaluate each such term, and jump over all the
+  ** generated code if the result is not true.  
+  **
+  ** Do not do this if the expression contains non-deterministic functions
+  ** that are not within a sub-select. This is not strictly required, but
+  ** preserves SQLite's legacy behaviour in the following two cases:
+  **
+  **   FROM ... WHERE random()>0;           -- eval random() once per row
+  **   FROM ... WHERE (SELECT random())>0;  -- eval random() once overall
+  */
+  for(ii=0; ii<sWLB.pWC->nTerm; ii++){
+    WhereTerm *pT = &sWLB.pWC->a[ii];
+    if( pT->prereqAll==0 && (nTabList==0 || exprIsDeterministic(pT->pExpr)) ){
+      sqlite3ExprIfFalse(pParse, pT->pExpr, pWInfo->iBreak, SQLITE_JUMPIFNULL);
+      pT->wtFlags |= TERM_CODED;
+    }
+  }
 
   if( wctrlFlags & WHERE_WANT_DISTINCT ){
     if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
       /* The DISTINCT marking is pointless.  Ignore it. */
       pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;

Index: test/eqp.test
==================================================================
--- test/eqp.test
+++ test/eqp.test
@@ -186,28 +186,28 @@
   1 0 0 {SCAN TABLE t1 AS sub}
 }
 do_eqp_test 3.1.2 {
   SELECT * FROM t1 WHERE (SELECT x FROM t1 AS sub);
 } {
-  0 0 0 {SCAN TABLE t1}
   0 0 0 {EXECUTE SCALAR SUBQUERY 1}
   1 0 0 {SCAN TABLE t1 AS sub}
+  0 0 0 {SCAN TABLE t1}
 }
 do_eqp_test 3.1.3 {
   SELECT * FROM t1 WHERE (SELECT x FROM t1 AS sub ORDER BY y);
 } {
-  0 0 0 {SCAN TABLE t1}
   0 0 0 {EXECUTE SCALAR SUBQUERY 1}
   1 0 0 {SCAN TABLE t1 AS sub}
   1 0 0 {USE TEMP B-TREE FOR ORDER BY}
+  0 0 0 {SCAN TABLE t1}
 }
 do_eqp_test 3.1.4 {
   SELECT * FROM t1 WHERE (SELECT x FROM t2 ORDER BY x);
 } {
-  0 0 0 {SCAN TABLE t1}
   0 0 0 {EXECUTE SCALAR SUBQUERY 1}
   1 0 0 {SCAN TABLE t2 USING COVERING INDEX t2i1}
+  0 0 0 {SCAN TABLE t1}
 }
 
 det 3.2.1 {
   SELECT * FROM (SELECT * FROM t1 ORDER BY x LIMIT 10) ORDER BY y LIMIT 5
 } {

Index: test/whereF.test
==================================================================
--- test/whereF.test
+++ test/whereF.test
@@ -116,7 +116,64 @@
   CREATE TABLE t4(a,b,c,d,e, PRIMARY KEY(a,b,c));
   CREATE INDEX t4adc ON t4(a,d,c);
   CREATE UNIQUE INDEX t4aebc ON t4(a,e,b,c);
   EXPLAIN QUERY PLAN SELECT rowid FROM t4 WHERE a=? AND b=?;
 } {/a=. AND b=./}
+
+#-------------------------------------------------------------------------
+# Test the following case:
+#
+#   ... FROM t1, t2 WHERE (
+#     t2.rowid = +t1.rowid OR (t2.f2 = t1.f1 AND t1.f1!=-1)
+#   )
+#
+# where there is an index on t2(f2). The planner should use "t1" as the
+# outer loop. The inner loop, on "t2", is an OR optimization. One pass
+# for:
+#
+#     t2.rowid = $1
+#
+# and another for:
+#
+#     t2.f2=$1 AND $1!=-1
+#
+# the test is to ensure that on the second pass, the ($1!=-1) condition
+# is tested before any seek operations are performed - i.e. outside of
+# the loop through the f2=$1 range of the t2(f2) index.
+#
+reset_db
+do_execsql_test 5.0 {
+  CREATE TABLE t1(f1);
+  CREATE TABLE t2(f2);
+  CREATE INDEX t2f ON t2(f2);
+
+  INSERT INTO t1 VALUES(-1);
+  INSERT INTO t1 VALUES(-1);
+  INSERT INTO t1 VALUES(-1);
+  INSERT INTO t1 VALUES(-1);
+
+  WITH w(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM w WHERE i<1000
+  )
+  INSERT INTO t2 SELECT -1 FROM w;
+}
+
+do_execsql_test 5.1 {
+  SELECT count(*) FROM t1, t2 WHERE t2.rowid = +t1.rowid
+} {4}
+do_test 5.2 { expr [db status vmstep]<200 } 1
+
+do_execsql_test 5.3 {
+  SELECT count(*) FROM t1, t2 WHERE (
+    t2.rowid = +t1.rowid OR t2.f2 = t1.f1
+  )
+} {4000}
+do_test 5.4 { expr [db status vmstep]>1000 } 1
+
+do_execsql_test 5.5 {
+  SELECT count(*) FROM t1, t2 WHERE (
+    t2.rowid = +t1.rowid OR (t2.f2 = t1.f1 AND t1.f1!=-1)
+  )
+} {4}
+do_test 5.6 { expr [db status vmstep]<200 } 1
 
 finish_test