From 8c6307adc2fbd31c1352336d4b76372a9a56b70c Mon Sep 17 00:00:00 2001
From: HuaiyuXu <391585975@qq.com>
Date: Wed, 29 May 2019 13:55:44 +0800
Subject: [PATCH] executor: reset groupChecker for StreamAggExec when Close
 (#10615)

---
 executor/aggregate.go      | 10 ++++++++++
 executor/aggregate_test.go | 11 +++++++++++
 2 files changed, 21 insertions(+)

diff --git a/executor/aggregate.go b/executor/aggregate.go
index fde12cb6bab8f..e8fa560797dab 100644
--- a/executor/aggregate.go
+++ b/executor/aggregate.go
@@ -789,6 +789,7 @@ func (e *StreamAggExec) Open(ctx context.Context) error {
 // Close implements the Executor Close interface.
 func (e *StreamAggExec) Close() error {
 	e.childResult = nil
+	e.groupChecker.reset()
 	return e.baseExecutor.Close()
 }
 
@@ -954,3 +955,12 @@ func (e *groupChecker) meetNewGroup(row chunk.Row) (bool, error) {
 	}
 	return !firstGroup, nil
 }
+
+func (e *groupChecker) reset() {
+	if e.curGroupKey != nil {
+		e.curGroupKey = e.curGroupKey[:0]
+	}
+	if e.tmpGroupKey != nil {
+		e.tmpGroupKey = e.tmpGroupKey[:0]
+	}
+}
diff --git a/executor/aggregate_test.go b/executor/aggregate_test.go
index 06826616d5564..98bc6d2e701d3 100644
--- a/executor/aggregate_test.go
+++ b/executor/aggregate_test.go
@@ -710,3 +710,14 @@ func (s *testSuite1) TestIssue10098(c *C) {
 	tk.MustExec("insert into t values('1', '222'), ('12', '22')")
 	tk.MustQuery("select group_concat(distinct a, b) from t").Check(testkit.Rows("1222,1222"))
 }
+
+func (s *testSuite1) TestIssue10608(c *C) {
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec(`drop table if exists t, s;`)
+	tk.MustExec("create table t(a int)")
+	tk.MustExec("create table s(a int, b int)")
+	tk.MustExec("insert into s values(100292, 508931), (120002, 508932)")
+	tk.MustExec("insert into t values(508931), (508932)")
+	tk.MustQuery("select (select group_concat(concat(123,'-')) from t where t.a = s.b group by t.a) as t from s;").Check(testkit.Rows("123-", "123-"))
+
+}