Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -189,13 +189,14 @@
                || sqlite3ExprCompare(pTerm->pExpr->pLeft,pScan->pIdxExpr,iCur)==0)
          && (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
         ){
           if( (pTerm->eOperator & WO_EQUIV)!=0
            && pScan->nEquiv<ArraySize(pScan->aiCur)
-           && (pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight))->op==TK_COLUMN
           ){
             int j;
+            pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
+            assert( pX->op==TK_COLUMN );
             for(j=0; j<pScan->nEquiv; j++){
               if( pScan->aiCur[j]==pX->iTable
                && pScan->aiColumn[j]==pX->iColumn ){
                   break;
               }