cmd/geth, cmd/devp2p: fix some cli parsing issues (#25234)

* cmd/geth: add some missing argument count checks

* internal/flags: skip cmds with no action func in MigrateGlobalFlags

* internal/flags: add Merge

* cmd/devp2p: re-add listener config flags in discv4 commands

cmd/geth/chaincmd.go

@@ -166,10 +166,12 @@ This command dumps out the state for a given block (or latest, if none provided)
 // initGenesis will initialise the given JSON format genesis file and writes it as
 // the zero'd block (i.e. genesis) or will fail hard if it can't succeed.
 func initGenesis(ctx *cli.Context) error {
-	// Make sure we have a valid genesis JSON
+	if ctx.Args().Len() != 1 {
+		utils.Fatalf("need genesis.json file as the only argument")
+	}
 	genesisPath := ctx.Args().First()
 	if len(genesisPath) == 0 {
-		utils.Fatalf("Must supply path to genesis JSON file")
+		utils.Fatalf("invalid path to genesis file")
 	}
 	file, err := os.Open(genesisPath)
 	if err != nil {

cmd/geth/consolecmd.go

@@ -114,6 +114,10 @@ func localConsole(ctx *cli.Context) error {
 // remoteConsole will connect to a remote geth instance, attaching a JavaScript
 // console to it.
 func remoteConsole(ctx *cli.Context) error {
+	if ctx.Args().Len() > 1 {
+		utils.Fatalf("invalid command-line: too many arguments")
+	}
+
 	endpoint := ctx.Args().First()
 	if endpoint == "" {
 		cfg := defaultNodeConfig()