fix(mempool): fix mempool.max-txs flag not using desired default of 0 (cosmos#794)

* add explicit override for viper config default

* add changelog

* check error and panic

Author: almk-dev

CHANGELOG.md

@@ -15,6 +15,7 @@
 
 ### BUG FIXES
 
+- [\#794](https://github.com/cosmos/evm/pull/794) Fix mempool.max-txs flag not using desired default of 0
 - [\#748](https://github.com/cosmos/evm/pull/748) Fix DynamicFeeChecker in Cosmos ante handler to respect NoBaseFee feemarkets' parameter.
 - [\#690](https://github.com/cosmos/evm/pull/690) Fix Ledger hardware wallet support for coin type 60.
 - [\#766](https://github.com/cosmos/evm/pull/766) Align gas estimation logic with go-ethereum v1.16.3

evmd/mempool.go

@@ -2,6 +2,7 @@ package evmd
 
 import (
 	"fmt"
+
 	"github.com/cosmos/evm/server"
 
 	"cosmossdk.io/log"

server/server_app_options.go

@@ -16,6 +16,7 @@ import (
 	sdkserver "github.com/cosmos/cosmos-sdk/server"
 	servertypes "github.com/cosmos/cosmos-sdk/server/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkmempool "github.com/cosmos/cosmos-sdk/types/mempool"
 	genutiltypes "github.com/cosmos/cosmos-sdk/x/genutil/types"
 )
 
@@ -145,8 +146,10 @@ func GetLegacyPoolConfig(appOpts servertypes.AppOptions, logger log.Logger) *leg
 
 func GetCosmosPoolMaxTx(appOpts servertypes.AppOptions, logger log.Logger) int {
 	if appOpts == nil {
-		logger.Error("app options is nil, using default cosmos pool max tx of -1 (no-op)")
-		return 0
+		// we don't want to return 0 here, as then appOpts.Get() will return nil and that will be
+		// "accidentally" cast to the correct evm max tx default of 0, thereby hiding the error
+		logger.Error("app options is nil, using sdk max tx default of -1 (no-op)")
+		return sdkmempool.DefaultMaxTx
 	}
 
 	return cast.ToInt(appOpts.Get(sdkserver.FlagMempoolMaxTxs))

server/start.go

@@ -184,7 +184,12 @@ which accepts a path for the resulting pprof file.
 	cmd.Flags().Uint(server.FlagInvCheckPeriod, 0, "Assert registered invariants every N blocks")
 	cmd.Flags().Uint64(server.FlagMinRetainBlocks, 0, "Minimum block height offset during ABCI commit to prune CometBFT blocks")
 	cmd.Flags().String(srvflags.AppDBBackend, "", "The type of database for application and snapshots databases")
+
 	cmd.Flags().Int32(server.FlagMempoolMaxTxs, 0, "The maximum number of transactions in the mempool")
+	// explicitly override the app.toml default value, as normally config file takes precedence over flag defaults
+	if err := cmd.Flags().Set(server.FlagMempoolMaxTxs, "0"); err != nil {
+		panic(err)
+	}
 
 	cmd.Flags().Bool(srvflags.GRPCOnly, false, "Start the node in gRPC query only mode without CometBFT process")
 	cmd.Flags().Bool(srvflags.GRPCEnable, cosmosevmserverconfig.DefaultGRPCEnable, "Define if the gRPC server should be enabled")