From 6f4dd17216ce4cb161ad8f2b7a96acdd4af2f6af Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Fri, 13 Aug 2021 17:55:59 +0800
Subject: [PATCH] planner: Fix the problem that
 `PlanBuilder.buildWindowFunctions` may change sub operator's schema. (#27176)
 (#27204)

---
 expression/aggregation/base_func.go  | 2 +-
 planner/core/logical_plan_builder.go | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/expression/aggregation/base_func.go b/expression/aggregation/base_func.go
index 1a1a7543ef29a..64dbcd2e88689 100644
--- a/expression/aggregation/base_func.go
+++ b/expression/aggregation/base_func.go
@@ -432,7 +432,7 @@ func (a *baseFuncDesc) WrapCastForAggArgs(ctx sessionctx.Context) {
 		if col, ok := a.Args[i].(*expression.Column); ok {
 			col.RetType = types.NewFieldType(col.RetType.Tp)
 		}
-		// originTp is used when the the `Tp` of column is TypeFloat32 while
+		// originTp is used when the `Tp` of column is TypeFloat32 while
 		// the type of the aggregation function is TypeFloat64.
 		originTp := a.Args[i].GetType().Tp
 		*(a.Args[i].GetType()) = *(a.RetTp)
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index 76566d93ac61a..0d2aecf3f0083 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -4511,7 +4511,7 @@ func (b *PlanBuilder) buildProjectionForWindow(ctx context.Context, p LogicalPla
 		p = np
 		switch newArg.(type) {
 		case *expression.Column, *expression.Constant:
-			newArgList = append(newArgList, newArg)
+			newArgList = append(newArgList, newArg.Clone())
 			continue
 		}
 		proj.Exprs = append(proj.Exprs, newArg)
@@ -4543,7 +4543,7 @@ func (b *PlanBuilder) buildArgs4WindowFunc(ctx context.Context, p LogicalPlan, a
 		p = np
 		switch newArg.(type) {
 		case *expression.Column, *expression.Constant:
-			newArgList = append(newArgList, newArg)
+			newArgList = append(newArgList, newArg.Clone())
 			continue
 		}
 		col := &expression.Column{