parser, variable: fix #5478, make 'set transaction read only' works. (#5491)

Author: winkyao

expression/integration_test.go

@@ -2918,6 +2918,25 @@ func (s *testIntegrationSuite) TestSetVariables(c *C) {
 	_, err = tk.Exec("INSERT INTO tab0 select cast('999:44:33' as time);")
 	c.Assert(err, NotNil)
 	c.Assert(err.Error(), Equals, "[types:1292]Truncated incorrect time value: '999h44m33s'")
+
+	// issue #5478
+	_, err = tk.Exec("set session transaction read write;")
+	_, err = tk.Exec("set global transaction read write;")
+	r = tk.MustQuery(`select @@session.tx_read_only, @@global.tx_read_only, @@session.transaction_read_only, @@global.transaction_read_only;`)
+	r.Check(testkit.Rows("0 0 0 0"))
+
+	_, err = tk.Exec("set session transaction read only;")
+	c.Assert(err, IsNil)
+	r = tk.MustQuery(`select @@session.tx_read_only, @@global.tx_read_only, @@session.transaction_read_only, @@global.transaction_read_only;`)
+	r.Check(testkit.Rows("1 0 1 0"))
+	_, err = tk.Exec("set global transaction read only;")
+	r = tk.MustQuery(`select @@session.tx_read_only, @@global.tx_read_only, @@session.transaction_read_only, @@global.transaction_read_only;`)
+	r.Check(testkit.Rows("1 1 1 1"))
+
+	_, err = tk.Exec("set session transaction read write;")
+	_, err = tk.Exec("set global transaction read write;")
+	r = tk.MustQuery(`select @@session.tx_read_only, @@global.tx_read_only, @@session.transaction_read_only, @@global.transaction_read_only;`)
+	r.Check(testkit.Rows("0 0 0 0"))
 }
 
 func (s *testIntegrationSuite) TestIssue4954(c *C) {

parser/parser.y

@@ -4217,15 +4217,16 @@ TransactionChars:
 	TransactionChar
 	{
 		if $1 != nil {
-			$$ = []*ast.VariableAssignment{$1.(*ast.VariableAssignment)}
+			$$ = $1
 		} else {
 			$$ = []*ast.VariableAssignment{}
 		}
 	}
 |	TransactionChars ',' TransactionChar
 	{
 		if $3 != nil {
-			$$ = append($1.([]*ast.VariableAssignment), $3.(*ast.VariableAssignment))
+			varAssigns := $3.([]*ast.VariableAssignment)
+			$$ = append($1.([]*ast.VariableAssignment), varAssigns...)
 		} else {
 			$$ = $1
 		}
@@ -4234,18 +4235,26 @@ TransactionChars:
 TransactionChar:
 	"ISOLATION" "LEVEL" IsolationLevel
 	{
+		varAssigns := []*ast.VariableAssignment{}
 		expr := ast.NewValueExpr($3)
-		$$ = &ast.VariableAssignment{Name: "tx_isolation", Value: expr, IsSystem: true}
+		varAssigns = append(varAssigns, &ast.VariableAssignment{Name: "tx_isolation", Value: expr, IsSystem: true})
+		$$ = varAssigns
 	}
 |	"READ" "WRITE"
 	{
-		// Parsed but ignored
-		$$ = nil
+		varAssigns := []*ast.VariableAssignment{}
+		expr := ast.NewValueExpr("0")
+		varAssigns = append(varAssigns, &ast.VariableAssignment{Name: "tx_read_only", Value: expr, IsSystem: true})
+		varAssigns = append(varAssigns, &ast.VariableAssignment{Name: "transaction_read_only", Value: expr, IsSystem: true})
+		$$ = varAssigns
 	}
 |	"READ" "ONLY"
 	{
-		// Parsed but ignored
-		$$ = nil
+		varAssigns := []*ast.VariableAssignment{}
+		expr := ast.NewValueExpr("1")
+		varAssigns = append(varAssigns, &ast.VariableAssignment{Name: "tx_read_only", Value: expr, IsSystem: true})
+		varAssigns = append(varAssigns, &ast.VariableAssignment{Name: "transaction_read_only", Value: expr, IsSystem: true})
+		$$ = varAssigns
 	}
 
 IsolationLevel:

sessionctx/variable/sysvar.go

@@ -162,7 +162,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeNone, "thread_stack", "262144"},
 	{ScopeGlobal, "relay_log_info_repository", "FILE"},
 	{ScopeGlobal | ScopeSession, "sql_log_bin", "ON"},
-	{ScopeGlobal, "super_read_only", ""},
+	{ScopeGlobal, "super_read_only", "OFF"},
 	{ScopeGlobal | ScopeSession, "max_delayed_threads", "20"},
 	{ScopeNone, "protocol_version", "10"},
 	{ScopeGlobal | ScopeSession, "new", "OFF"},
@@ -391,6 +391,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeGlobal | ScopeSession, "net_write_timeout", "60"},
 	{ScopeGlobal, "innodb_buffer_pool_load_abort", "OFF"},
 	{ScopeGlobal | ScopeSession, "tx_isolation", "REPEATABLE-READ"},
+	{ScopeGlobal | ScopeSession, "transaction_isolation", "REPEATABLE-READ"},
 	{ScopeGlobal | ScopeSession, "collation_connection", "latin1_swedish_ci"},
 	{ScopeGlobal, "rpl_semi_sync_master_timeout", ""},
 	{ScopeGlobal | ScopeSession, "transaction_prealloc_size", "4096"},
@@ -494,6 +495,7 @@ var defaultSysVars = []*SysVar{
 	{ScopeNone, "performance_schema_events_waits_history_size", "10"},
 	{ScopeGlobal, "log_syslog_tag", ""},
 	{ScopeGlobal | ScopeSession, "tx_read_only", "0"},
+	{ScopeGlobal | ScopeSession, "transaction_read_only", "0"},
 	{ScopeGlobal, "rpl_semi_sync_master_wait_point", ""},
 	{ScopeGlobal, "innodb_undo_log_truncate", ""},
 	{ScopeNone, "simplified_binlog_gtid_recovery", "OFF"},