*: session variable value should not be modified when get global vari…

…able (#5317)
pingcap · Dec 6, 2017 · 738f933 · 738f933
1 parent b0cd155
commit 738f933
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/new_session_test.go b/new_session_test.go
@@ -296,6 +296,17 @@ func (s *testSessionSuite) TestGlobalVarAccessor(c *C) {
 	result.Check(testkit.Rows("sql_select_limit 18446744073709551615"))
 	result = tk.MustQuery("show session variables where variable_name='sql_select_limit';")
 	result.Check(testkit.Rows("sql_select_limit 100000000000"))
+
+	result = tk.MustQuery("select @@global.autocommit;")
+	result.Check(testkit.Rows("ON"))
+	result = tk.MustQuery("select @@autocommit;")
+	result.Check(testkit.Rows("ON"))
+	tk.MustExec("set @@global.autocommit = 0;")
+	result = tk.MustQuery("select @@global.autocommit;")
+	result.Check(testkit.Rows("0"))
+	result = tk.MustQuery("select @@autocommit;")
+	result.Check(testkit.Rows("ON"))
+	tk.MustExec("set @@global.autocommit=1")
 }
 
 func (s *testSessionSuite) TestRetryResetStmtCtx(c *C) {

diff --git a/sessionctx/varsutil/varsutil.go b/sessionctx/varsutil/varsutil.go
@@ -76,7 +76,6 @@ func GetGlobalSystemVar(s *variable.SessionVars, key string) (string, error) {
 	if err != nil {
 		return "", errors.Trace(err)
 	}
-	s.Systems[key] = gVal
 	return gVal, nil
 }