From c4befe61bce4f174192e60d9385cdd0268a0a993 Mon Sep 17 00:00:00 2001
From: HuaiyuXu <391585975@qq.com>
Date: Fri, 25 Oct 2019 16:43:13 +0800
Subject: [PATCH] =?UTF-8?q?planner/core:=20do=20not=20change=20window=20as?=
 =?UTF-8?q?t=20when=20building=20plan=20(#12=E2=80=A6=20(#12934)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 planner/core/logical_plan_builder.go | 10 +++---
 planner/core/logical_plan_test.go    | 50 +++++++++++++++++++---------
 2 files changed, 40 insertions(+), 20 deletions(-)

diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index b172635bc1dde..b196e36146b61 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -3350,7 +3350,10 @@ func (b *PlanBuilder) checkOriginWindowSpecs(funcs []*ast.WindowFuncExpr, orderB
 		if f.FromLast {
 			return ErrNotSupportedYet.GenWithStackByArgs("FROM LAST")
 		}
-		spec := f.Spec
+		spec := &f.Spec
+		if f.Spec.Name.L != "" {
+			spec = b.windowSpecs[f.Spec.Name.L]
+		}
 		if spec.Frame == nil {
 			continue
 		}
@@ -3371,11 +3374,11 @@ func (b *PlanBuilder) checkOriginWindowSpecs(funcs []*ast.WindowFuncExpr, orderB
 			return ErrWindowFrameIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
 		}
 
-		err := b.checkOriginWindowFrameBound(&start, &spec, orderByItems)
+		err := b.checkOriginWindowFrameBound(&start, spec, orderByItems)
 		if err != nil {
 			return err
 		}
-		err = b.checkOriginWindowFrameBound(&end, &spec, orderByItems)
+		err = b.checkOriginWindowFrameBound(&end, spec, orderByItems)
 		if err != nil {
 			return err
 		}
@@ -3483,7 +3486,6 @@ func (b *PlanBuilder) groupWindowFuncs(windowFuncs []*ast.WindowFuncExpr) (map[*
 		if !ok {
 			return nil, ErrWindowNoSuchWindow.GenWithStackByArgs(windowFunc.Spec.Name.O)
 		}
-		windowFunc.Spec = *spec
 		newSpec, updated := b.handleDefaultFrame(spec, windowFunc.F)
 		if !updated {
 			groupedWindow[spec] = append(groupedWindow[spec], windowFunc)
diff --git a/planner/core/logical_plan_test.go b/planner/core/logical_plan_test.go
index 47c7f24d58ca5..88446a70c998e 100644
--- a/planner/core/logical_plan_test.go
+++ b/planner/core/logical_plan_test.go
@@ -23,6 +23,7 @@ import (
 	. "github.com/pingcap/check"
 	"github.com/pingcap/parser"
 	"github.com/pingcap/parser/ast"
+	"github.com/pingcap/parser/format"
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/parser/terror"
@@ -2512,31 +2513,48 @@ func (s *testPlanSuite) TestWindowFunction(c *C) {
 	ctx := context.TODO()
 	for i, tt := range tests {
 		comment := Commentf("case:%v sql:%s", i, tt.sql)
-		stmt, err := s.ParseOneStmt(tt.sql, "", "")
-		c.Assert(err, IsNil, comment)
-		Preprocess(s.ctx, stmt, s.is)
-		builder := &PlanBuilder{
-			ctx:           MockContext(),
-			is:            s.is,
-			colMapper:     make(map[*ast.ColumnNameExpr]int),
-			hintProcessor: &BlockHintProcessor{},
-		}
-		p, err := builder.Build(ctx, stmt)
+		p, stmt, err := s.optimize(ctx, tt.sql)
 		if err != nil {
 			c.Assert(err.Error(), Equals, tt.result, comment)
 			continue
 		}
+		c.Assert(ToString(p), Equals, tt.result, comment)
+
+		var sb strings.Builder
+		// After restore, the result should be the same.
+		err = stmt.Restore(format.NewRestoreCtx(format.DefaultRestoreFlags, &sb))
 		c.Assert(err, IsNil)
-		p, err = logicalOptimize(ctx, builder.optFlag, p.(LogicalPlan))
-		c.Assert(err, IsNil)
-		lp, ok := p.(LogicalPlan)
-		c.Assert(ok, IsTrue)
-		p, err = physicalOptimize(lp)
-		c.Assert(err, IsNil)
+		p, _, err = s.optimize(ctx, sb.String())
+		if err != nil {
+			c.Assert(err.Error(), Equals, tt.result, comment)
+			continue
+		}
 		c.Assert(ToString(p), Equals, tt.result, comment)
 	}
 }
 
+func (s *testPlanSuite) optimize(ctx context.Context, sql string) (PhysicalPlan, ast.Node, error) {
+	stmt, err := s.ParseOneStmt(sql, "", "")
+	if err != nil {
+		return nil, nil, err
+	}
+	err = Preprocess(s.ctx, stmt, s.is)
+	if err != nil {
+		return nil, nil, err
+	}
+	builder := NewPlanBuilder(MockContext(), s.is, &BlockHintProcessor{})
+	p, err := builder.Build(ctx, stmt)
+	if err != nil {
+		return nil, nil, err
+	}
+	p, err = logicalOptimize(ctx, builder.optFlag, p.(LogicalPlan))
+	if err != nil {
+		return nil, nil, err
+	}
+	p, err = physicalOptimize(p.(LogicalPlan))
+	return p.(PhysicalPlan), stmt, err
+}
+
 func byItemsToProperty(byItems []*ByItems) *property.PhysicalProperty {
 	pp := &property.PhysicalProperty{}
 	for _, item := range byItems {