Index: src/expr.c
==================================================================
--- src/expr.c
+++ src/expr.c
@@ -2242,19 +2242,10 @@
     default: break;
   }
   return rc;
 }
 
-/*
-** Return true if p is a Column node that references a virtual table.
-*/
-int sqlite3ExprIsVtabRef(Expr *p){
-  if( p->op!=TK_COLUMN ) return 0;
-  if( p->y.pTab==0 ) return 0;
-  return IsVirtual(p->y.pTab);
-}
-
 /*
 ** Return FALSE if there is no chance that the expression can be NULL.
 **
 ** If the expression might be NULL or if the expression is too complex
 ** to tell return TRUE.  
@@ -5479,23 +5470,29 @@
     case TK_EQ:
     case TK_NE:
     case TK_LT:
     case TK_LE:
     case TK_GT:
-    case TK_GE:
+    case TK_GE: {
+      Expr *pLeft = pExpr->pLeft;
+      Expr *pRight = pExpr->pRight;
       testcase( pExpr->op==TK_EQ );
       testcase( pExpr->op==TK_NE );
       testcase( pExpr->op==TK_LT );
       testcase( pExpr->op==TK_LE );
       testcase( pExpr->op==TK_GT );
       testcase( pExpr->op==TK_GE );
-      if( sqlite3ExprIsVtabRef(pExpr->pLeft)
-       || sqlite3ExprIsVtabRef(pExpr->pRight)
+      /* The y.pTab=0 assignment in wherecode.c always happens after the
+      ** impliesNotNullRow() test */
+      if( (pLeft->op==TK_COLUMN && ALWAYS(pLeft->y.pTab!=0)
+                               && IsVirtual(pLeft->y.pTab))
+       || (pRight->op==TK_COLUMN && ALWAYS(pRight->y.pTab!=0)
+                               && IsVirtual(pRight->y.pTab))
       ){
-       return WRC_Prune;
+        return WRC_Prune;
       }
-
+    }
     default:
       return WRC_Continue;
   }
 }
 

Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -2151,12 +2151,15 @@
 ** done as a macro so that it will be optimized out when virtual
 ** table support is omitted from the build.
 */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 #  define IsVirtual(X)      ((X)->nModuleArg)
+#  define ExprIsVtab(X)  \
+              ((X)->op==TK_COLUMN && (X)->y.pTab!=0 && (X)->y.pTab->nModuleArg)
 #else
 #  define IsVirtual(X)      0
+#  define ExprIsVtab(X)     0
 #endif
 
 /*
 ** Macros to determine if a column is hidden.  IsOrdinaryHiddenColumn()
 ** only works for non-virtual tables (ordinary tables and views) and is
@@ -4276,11 +4279,10 @@
 int sqlite3ExprIsTableConstant(Expr*,int);
 #ifdef SQLITE_ENABLE_CURSOR_HINTS
 int sqlite3ExprContainsSubquery(Expr*);
 #endif
 int sqlite3ExprIsInteger(Expr*, int*);
-int sqlite3ExprIsVtabRef(Expr*);
 int sqlite3ExprCanBeNull(const Expr*);
 int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
 int sqlite3IsRowid(const char*);
 void sqlite3GenerateRowDelete(
     Parse*,Table*,Trigger*,int,int,int,i16,u8,u8,u8,int);

Index: src/whereexpr.c
==================================================================
--- src/whereexpr.c
+++ src/whereexpr.c
@@ -375,11 +375,12 @@
     **
     **       vtab_column MATCH expression
     **       MATCH(expression,vtab_column)
     */
     pCol = pList->a[1].pExpr;
-    if( sqlite3ExprIsVtabRef(pCol) ){
+    testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
+    if( ExprIsVtab(pCol) ){
       for(i=0; i<ArraySize(aOp); i++){
         if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
           *peOp2 = aOp[i].eOp2;
           *ppRight = pList->a[0].pExpr;
           *ppLeft = pCol;
@@ -397,11 +398,12 @@
     ** Historically, xFindFunction expected to see lower-case function
     ** names.  But for this use case, xFindFunction is expected to deal
     ** with function names in an arbitrary case.
     */
     pCol = pList->a[0].pExpr;
-    if( sqlite3ExprIsVtabRef(pCol) ){
+    testcase( pCol->op==TK_COLUMN && pCol->y.pTab==0 );
+    if( ExprIsVtab(pCol) ){
       sqlite3_vtab *pVtab;
       sqlite3_module *pMod;
       void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**);
       void *pNotUsed;
       pVtab = sqlite3GetVTable(db, pCol->y.pTab)->pVtab;
@@ -420,14 +422,16 @@
     }
   }else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){
     int res = 0;
     Expr *pLeft = pExpr->pLeft;
     Expr *pRight = pExpr->pRight;
-    if( sqlite3ExprIsVtabRef(pLeft) ){
+    testcase( pLeft->op==TK_COLUMN && pLeft->y.pTab==0 );
+    if( ExprIsVtab(pLeft) ){
       res++;
     }
-    if( pRight && sqlite3ExprIsVtabRef(pRight) ){
+    testcase( pRight && pRight->op==TK_COLUMN && pRight->y.pTab==0 );
+    if( pRight && ExprIsVtab(pRight) ){
       res++;
       SWAP(Expr*, pLeft, pRight);
     }
     *ppLeft = pLeft;
     *ppRight = pRight;

