cmd, eth: fix dump config issue (#19825)

* eth: fix error when dump config with nil checkpoint

* cmd/utils: ignore default datadir if it's already set.

cmd/utils/flags.go

@@ -1202,11 +1202,11 @@ func setDataDir(ctx *cli.Context, cfg *node.Config) {
 		cfg.DataDir = ctx.GlobalString(DataDirFlag.Name)
 	case ctx.GlobalBool(DeveloperFlag.Name):
 		cfg.DataDir = "" // unless explicitly requested, use memory databases
-	case ctx.GlobalBool(TestnetFlag.Name):
+	case ctx.GlobalBool(TestnetFlag.Name) && cfg.DataDir == node.DefaultDataDir():
 		cfg.DataDir = filepath.Join(node.DefaultDataDir(), "testnet")
-	case ctx.GlobalBool(RinkebyFlag.Name):
+	case ctx.GlobalBool(RinkebyFlag.Name) && cfg.DataDir == node.DefaultDataDir():
 		cfg.DataDir = filepath.Join(node.DefaultDataDir(), "rinkeby")
-	case ctx.GlobalBool(GoerliFlag.Name):
+	case ctx.GlobalBool(GoerliFlag.Name) && cfg.DataDir == node.DefaultDataDir():
 		cfg.DataDir = filepath.Join(node.DefaultDataDir(), "goerli")
 	}
 }

eth/config.go

@@ -150,8 +150,8 @@ type Config struct {
 	RPCGasCap *big.Int `toml:",omitempty"`
 
 	// Checkpoint is a hardcoded checkpoint which can be nil.
-	Checkpoint *params.TrustedCheckpoint
+	Checkpoint *params.TrustedCheckpoint `toml:",omitempty"`
 
 	// CheckpointOracle is the configuration for checkpoint oracle.
-	CheckpointOracle *params.CheckpointOracleConfig
+	CheckpointOracle *params.CheckpointOracleConfig `toml:",omitempty"`
 }

eth/gen_config.go

@@ -46,9 +46,9 @@ func (c Config) MarshalTOML() (interface{}, error) {
 		DocRoot                 string `toml:"-"`
 		EWASMInterpreter        string
 		EVMInterpreter          string
-		RPCGasCap               *big.Int `toml:",omitempty"`
-		Checkpoint              *params.TrustedCheckpoint
-		CheckpointOracle        *params.CheckpointOracleConfig
+		RPCGasCap               *big.Int                       `toml:",omitempty"`
+		Checkpoint              *params.TrustedCheckpoint      `toml:",omitempty"`
+		CheckpointOracle        *params.CheckpointOracleConfig `toml:",omitempty"`
 	}
 	var enc Config
 	enc.Genesis = c.Genesis
@@ -116,9 +116,9 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 		DocRoot                 *string `toml:"-"`
 		EWASMInterpreter        *string
 		EVMInterpreter          *string
-		RPCGasCap               *big.Int `toml:",omitempty"`
-		Checkpoint              *params.TrustedCheckpoint
-		CheckpointOracle        *params.CheckpointOracleConfig
+		RPCGasCap               *big.Int                       `toml:",omitempty"`
+		Checkpoint              *params.TrustedCheckpoint      `toml:",omitempty"`
+		CheckpointOracle        *params.CheckpointOracleConfig `toml:",omitempty"`
 	}
 	var dec Config
 	if err := unmarshal(&dec); err != nil {