From 1fec74ba37fe139099ca41770a99b5508c2790b2 Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Mon, 15 Apr 2024 17:10:38 +0800
Subject: [PATCH] config: return error when `toml.DecodeFile` failed. (#51828)
 (#52577)

close pingcap/tidb#51399
---
 config/BUILD.bazel    |  2 +-
 config/config.go      |  5 ++++-
 config/config_test.go | 22 ++++++++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/config/BUILD.bazel b/config/BUILD.bazel
index db2e165331bca..299e001e2cf90 100644
--- a/config/BUILD.bazel
+++ b/config/BUILD.bazel
@@ -37,7 +37,7 @@ go_test(
     data = glob(["**"]),
     embed = [":config"],
     flaky = True,
-    shard_count = 23,
+    shard_count = 24,
     deps = [
         "//testkit/testsetup",
         "//util/logutil",
diff --git a/config/config.go b/config/config.go
index 63c181d51675e..508dbe27fca60 100644
--- a/config/config.go
+++ b/config/config.go
@@ -1237,13 +1237,16 @@ func (c *Config) RemovedVariableCheck(confFile string) error {
 // Load loads config options from a toml file.
 func (c *Config) Load(confFile string) error {
 	metaData, err := toml.DecodeFile(confFile, c)
+	if err != nil {
+		return err
+	}
 	if c.TokenLimit == 0 {
 		c.TokenLimit = 1000
 	}
 	// If any items in confFile file are not mapped into the Config struct, issue
 	// an error and stop the server from starting.
 	undecoded := metaData.Undecoded()
-	if len(undecoded) > 0 && err == nil {
+	if len(undecoded) > 0 {
 		var undecodedItems []string
 		for _, item := range undecoded {
 			undecodedItems = append(undecodedItems, item.String())
diff --git a/config/config_test.go b/config/config_test.go
index 5523165b935d9..42307f3e37280 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -1329,3 +1329,25 @@ func TestAutoScalerConfig(t *testing.T) {
 		conf.UseAutoScaler = false
 	})
 }
+
+func TestInvalidConfigWithDeprecatedConfig(t *testing.T) {
+	tmpDir := t.TempDir()
+	configFile := filepath.Join(tmpDir, "config.toml")
+
+	f, err := os.Create(configFile)
+	require.NoError(t, err)
+
+	_, err = f.WriteString(`
+[log]
+slow-threshold = 1000
+[performance]
+enforce-mpp = 1
+	`)
+	require.NoError(t, err)
+	require.NoError(t, f.Sync())
+
+	var conf Config
+	err = conf.Load(configFile)
+	require.Error(t, err)
+	require.Equal(t, err.Error(), "toml: line 5 (last key \"performance.enforce-mpp\"): incompatible types: TOML value has type int64; destination has type boolean")
+}