executor: fix issue of getting stuck when querying information_schema…

….columns (pingcap#18847) (pingcap#18849) Signed-off-by: ti-srebot <ti-srebot@pingcap.com>
ti-srebot · Jul 29, 2020 · 2e3db79 · 2e3db79
1 parent 3c74fec
commit 2e3db79
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/executor/infoschema_reader.go b/executor/infoschema_reader.go
@@ -535,12 +535,12 @@ func (e *hugeMemTableRetriever) setDataForColumns(ctx sessionctx.Context) error
 		schema := e.dbs[e.dbsIdx]
 		for e.tblIdx < len(schema.Tables) {
 			table := schema.Tables[e.tblIdx]
+			e.tblIdx++
 			if checker != nil && !checker.RequestVerification(ctx.GetSessionVars().ActiveRoles, schema.Name.L, table.Name.L, "", mysql.AllPrivMask) {
 				continue
 			}
 
 			e.dataForColumnsInTable(schema, table)
-			e.tblIdx++
 			if len(e.rows) >= batch {
 				return nil
 			}

diff --git a/infoschema/tables_test.go b/infoschema/tables_test.go
@@ -1124,6 +1124,18 @@ func (s *testTableSuite) TestStmtSummaryTable(c *C) {
 	}, nil, nil)
 }
 
+func (s *testTableSuite) TestIssue18845(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec(`CREATE USER 'user18845'@'localhost';`)
+	tk.Se.Auth(&auth.UserIdentity{
+		Username:     "user18845",
+		Hostname:     "localhost",
+		AuthUsername: "user18845",
+		AuthHostname: "localhost",
+	}, nil, nil)
+	tk.MustQuery(`select count(*) from information_schema.columns;`)
+}
+
 // Test statements_summary_history.
 func (s *testTableSuite) TestStmtSummaryHistoryTable(c *C) {
 	tk := s.newTestKitWithRoot(c)