1 files changed, 13 insertions, 10 deletions
diff --git a/src/expr.c b/src/expr.c
index ebaf13af1..9ffc3bade 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1113,9 +1113,9 @@ Select *sqlite3ExprListToValues(Parse *pParse, int nElem, ExprList *pEList){
 ** Join two expressions using an AND operator.  If either expression is
 ** NULL, then just return the other expression.
 **
-** If one side or the other of the AND is known to be false, then instead
-** of returning an AND expression, just return a constant expression with
-** a value of false.
+** If one side or the other of the AND is known to be false, and neither side
+** is part of an ON clause, then instead of returning an AND expression,
+** just return a constant expression with a value of false.
 */
 Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
   sqlite3 *db = pParse->db;
@@ -1123,14 +1123,17 @@ Expr *sqlite3ExprAnd(Parse *pParse, Expr *pLeft, Expr *pRight){
     return pRight;
   }else if( pRight==0 ){
     return pLeft;
-  }else if( (ExprAlwaysFalse(pLeft) || ExprAlwaysFalse(pRight)) 
-         && !IN_RENAME_OBJECT
-  ){
-    sqlite3ExprDeferredDelete(pParse, pLeft);
-    sqlite3ExprDeferredDelete(pParse, pRight);
-    return sqlite3Expr(db, TK_INTEGER, "0");
   }else{
-    return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
+    u32 f = pLeft->flags | pRight->flags;
+    if( (f&(EP_OuterON|EP_InnerON|EP_IsFalse))==EP_IsFalse 
+     && !IN_RENAME_OBJECT
+    ){
+      sqlite3ExprDeferredDelete(pParse, pLeft);
+      sqlite3ExprDeferredDelete(pParse, pRight);
+      return sqlite3Expr(db, TK_INTEGER, "0");
+    }else{
+      return sqlite3PExpr(pParse, TK_AND, pLeft, pRight);
+    }
   }
 }