From ef3cf5ce731bdabd9e4dbb010830948529de4c30 Mon Sep 17 00:00:00 2001
From: xuhuaiyu <391585975@qq.com>
Date: Sat, 29 Sep 2018 16:29:42 +0800
Subject: [PATCH 1/3] ast, plan: return error when the arg of VALUES() function
 is not a column

---
 ast/expressions.go           | 5 ++++-
 plan/logical_plan_builder.go | 4 ++++
 plan/logical_plan_test.go    | 1 +
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/ast/expressions.go b/ast/expressions.go
index 24e510ff9e5a0..f839f2985d885 100644
--- a/ast/expressions.go
+++ b/ast/expressions.go
@@ -931,7 +931,10 @@ func (n *ValuesExpr) Accept(v Visitor) (Node, bool) {
 	if !ok {
 		return n, false
 	}
-	n.Column = node.(*ColumnNameExpr)
+	n.Column, ok = node.(*ColumnNameExpr)
+	if !ok {
+		n.Column = nil
+	}
 	return v.Leave(n)
 }
 
diff --git a/plan/logical_plan_builder.go b/plan/logical_plan_builder.go
index dcb0bb5e81171..949904239ea15 100644
--- a/plan/logical_plan_builder.go
+++ b/plan/logical_plan_builder.go
@@ -1140,6 +1140,10 @@ func (g *gbyResolver) Leave(inNode ast.Node) (ast.Node, bool) {
 			return inNode, false
 		}
 		return ret, true
+	case *ast.ValuesExpr:
+		if v.Column == nil {
+			g.err = ErrUnknownColumn.GenByArgs("", "VALUES() function")
+		}
 	}
 	return inNode, true
 }
diff --git a/plan/logical_plan_test.go b/plan/logical_plan_test.go
index 6a0f0133f79bc..ba07b1bf274a2 100644
--- a/plan/logical_plan_test.go
+++ b/plan/logical_plan_test.go
@@ -1752,6 +1752,7 @@ func (s *testPlanSuite) TestNameResolver(c *C) {
 		{"select a from t group by t11.c1", "[planner:1054]Unknown column 't11.c1' in 'group statement'"},
 		{"delete a from (select * from t ) as a, t", "[planner:1288]The target table a of the DELETE is not updatable"},
 		{"delete b from (select * from t ) as a, t", "[planner:1109]Unknown table 'b' in MULTI DELETE"},
+		{"select '' as fakeCol from t group by values(fakeCol)", "[planner:1054]Unknown column '' in 'VALUES() function'"},
 	}
 
 	for _, t := range tests {

From 7fcac680a4623ef67e0450d6fbf8d50f35dd1f40 Mon Sep 17 00:00:00 2001
From: xuhuaiyu <391585975@qq.com>
Date: Sat, 29 Sep 2018 16:50:56 +0800
Subject: [PATCH 2/3] fix ci

---
 planner/core/logical_plan_builder.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index 45a08561555f9..9ebf16ede572e 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -1166,7 +1166,7 @@ func (g *gbyResolver) Leave(inNode ast.Node) (ast.Node, bool) {
 		return ret, true
 	case *ast.ValuesExpr:
 		if v.Column == nil {
-			g.err = ErrUnknownColumn.GenByArgs("", "VALUES() function")
+			g.err = ErrUnknownColumn.GenWithStackByArgs("", "VALUES() function")
 		}
 	}
 	return inNode, true

From 68eeef3effc0c7bb1cbf5c87a987943f2fb223b5 Mon Sep 17 00:00:00 2001
From: xuhuaiyu <391585975@qq.com>
Date: Sun, 30 Sep 2018 11:33:13 +0800
Subject: [PATCH 3/3] address comment

---
 ast/expressions.go | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ast/expressions.go b/ast/expressions.go
index 6d98483e9d32b..e359b121c7444 100644
--- a/ast/expressions.go
+++ b/ast/expressions.go
@@ -927,10 +927,9 @@ func (n *ValuesExpr) Accept(v Visitor) (Node, bool) {
 	if !ok {
 		return n, false
 	}
+	// `node` may be *ast.ValueExpr, to avoid panic, we write `ok` but do not use
+	// it.
 	n.Column, ok = node.(*ColumnNameExpr)
-	if !ok {
-		n.Column = nil
-	}
 	return v.Leave(n)
 }