fix(config): mempool.max-txs configuration is invalid (#17649)

(cherry picked from commit b094b65)

CHANGELOG.md

@@ -49,6 +49,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ### Bug Fixes
 
 * (baseapp) [#17518](https://github.com/cosmos/cosmos-sdk/pull/17518) Utilizing voting power from vote extensions (CometBFT) instead of the current bonded tokens (x/staking) to determine if a set of vote extensions are valid.
+* (config) [#17649](https://github.com/cosmos/cosmos-sdk/pull/17649) Fix `mempool.max-txs` configuration is invalid in `app.config`.
 
 ## [v0.50.0-rc.0](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.50.0-rc.0) - 2023-08-18
 

server/config/config.go

@@ -166,7 +166,7 @@ type MempoolConfig struct {
 	// the mempool is disabled entirely, zero indicates that the mempool is
 	// unbounded in how many txs it may contain, and a positive value indicates
 	// the maximum amount of txs it may contain.
-	MaxTxs int
+	MaxTxs int `mapstructure:"max-txs"`
 }
 
 // State Streaming configuration

server/config/config_test.go

@@ -208,3 +208,21 @@ func TestSetConfigTemplate(t *testing.T) {
 	actual := setBuffer.String()
 	require.Equal(t, expected, actual, "resulting config strings")
 }
+
+func TestAppConfig(t *testing.T) {
+	appConfigFile := filepath.Join(t.TempDir(), "app.toml")
+	defer func() {
+		_ = os.Remove(appConfigFile)
+	}()
+
+	defAppConfig := DefaultConfig()
+	require.NoError(t, SetConfigTemplate(DefaultConfigTemplate))
+	require.NoError(t, WriteConfigFile(appConfigFile, defAppConfig))
+
+	v := viper.New()
+	v.SetConfigFile(appConfigFile)
+	require.NoError(t, v.ReadInConfig())
+	appCfg := new(Config)
+	require.NoError(t, v.Unmarshal(appCfg))
+	require.EqualValues(t, appCfg, defAppConfig)
+}

server/config/toml.go

@@ -234,7 +234,7 @@ stop-node-on-err = {{ .Streaming.ABCI.StopNodeOnErr }}
 #
 # Note, this configuration only applies to SDK built-in app-side mempool
 # implementations.
-max-txs = "{{ .Mempool.MaxTxs }}"
+max-txs = {{ .Mempool.MaxTxs }}
 `
 
 var configTemplate *template.Template