executor: fix analyze update panic cause by duplicate call analyze executor Close method

executor/explain.go

@@ -72,38 +72,33 @@ func (e *ExplainExec) Next(ctx context.Context, req *chunk.Chunk) error {
 	return nil
 }
 
-func (e *ExplainExec) generateExplainInfo(ctx context.Context) (rows [][]string, err error) {
-	closed := false
-	defer func() {
-		if !closed && e.analyzeExec != nil {
-			err = e.analyzeExec.Close()
-			closed = true
-		}
-	}()
+func (e *ExplainExec) executeAnalyzeExec(ctx context.Context) (err error) {
 	if e.analyzeExec != nil && !e.executed {
+		defer func() {
+			err1 := e.analyzeExec.Close()
+			if err1 != nil {
+				if err != nil {
+					err = errors.New(err.Error() + ", " + err1.Error())
+				} else {
+					err = err1
+				}
+			}
+		}()
 		e.executed = true
 		chk := newFirstChunk(e.analyzeExec)
-		var nextErr, closeErr error
 		for {
-			nextErr = Next(ctx, e.analyzeExec, chk)
-			if nextErr != nil || chk.NumRows() == 0 {
+			err = Next(ctx, e.analyzeExec, chk)
+			if err != nil || chk.NumRows() == 0 {
 				break
 			}
 		}
-		closeErr = e.analyzeExec.Close()
-		closed = true
-		if nextErr != nil {
-			if closeErr != nil {
-				err = errors.New(nextErr.Error() + ", " + closeErr.Error())
-			} else {
-				err = nextErr
-			}
-		} else if closeErr != nil {
-			err = closeErr
-		}
-		if err != nil {
-			return nil, err
-		}
+	}
+	return err
+}
+
+func (e *ExplainExec) generateExplainInfo(ctx context.Context) (rows [][]string, err error) {
+	if err = e.executeAnalyzeExec(ctx); err != nil {
+		return nil, err
 	}
 	if err = e.explain.RenderResult(); err != nil {
 		return nil, err

executor/explain_test.go

@@ -93,14 +93,15 @@ func (s *testSuite1) TestExplainWrite(c *C) {
 	tk := testkit.NewTestKitWithInit(c, s.store)
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t (a int)")
-	tk.MustExec("explain analyze insert into t select 1")
+	tk.MustQuery("explain analyze insert into t select 1")
 	tk.MustQuery("select * from t").Check(testkit.Rows("1"))
-	tk.MustExec("explain analyze update t set a=2 where a=1")
+	tk.MustQuery("explain analyze update t set a=2 where a=1")
 	tk.MustQuery("select * from t").Check(testkit.Rows("2"))
-	tk.MustExec("explain insert into t select 1")
+	tk.MustQuery("explain insert into t select 1")
 	tk.MustQuery("select * from t").Check(testkit.Rows("2"))
-	tk.MustExec("explain analyze insert into t select 1")
-	tk.MustQuery("select * from t order by a").Check(testkit.Rows("1", "2"))
+	tk.MustQuery("explain analyze insert into t select 1")
+	tk.MustQuery("explain analyze replace into t values (3)")
+	tk.MustQuery("select * from t order by a").Check(testkit.Rows("1", "2", "3"))
 }
 
 func (s *testSuite1) TestExplainAnalyzeMemory(c *C) {

executor/explain_unit_test.go

@@ -81,6 +81,10 @@ func TestExplainAnalyzeInvokeNextAndClose(t *testing.T) {
 		t.Errorf(err.Error())
 	}
 	// mockErrorOperator panic
+	explainExec = &ExplainExec{
+		baseExecutor: baseExec,
+		explain:      nil,
+	}
 	mockOpr = mockErrorOperator{baseExec, true, false}
 	explainExec.analyzeExec = &mockOpr
 	defer func() {