rpc: fix truncation (#598)

* rpc: fix truncation

* c++

CHANGELOG.md

@@ -56,6 +56,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (rpc) [tharsis#598](https://github.com/tharsis/ethermint/pull/598) Check truncation when creating a `BlockNumber` from `big.Int`
 * (evm) [tharsis#597](https://github.com/tharsis/ethermint/pull/597) Check for `uint64` -> `int64` block height overflow on `GetHashFn`
 * (evm) [tharsis#579](https://github.com/tharsis/ethermint/pull/579) Update `DeriveChainID` function to handle `v` signature values `< 35`.
 * (encoding) [tharsis#478](https://github.com/tharsis/ethermint/pull/478) Register `Evidence` to amino codec.

ethereum/rpc/types/block.go

@@ -9,13 +9,15 @@ import (
  "math/big"
  "strings"
 
- "github.com/ethereum/go-ethereum/common"
-
- grpctypes "github.com/cosmos/cosmos-sdk/types/grpc"
  "github.com/spf13/cast"
  "google.golang.org/grpc/metadata"
 
+ "github.com/ethereum/go-ethereum/common"
  "github.com/ethereum/go-ethereum/common/hexutil"
+
+ grpctypes "github.com/cosmos/cosmos-sdk/types/grpc"
+
+ ethermint "github.com/tharsis/ethermint/types"
 )
 
 // BlockNumber represents decoding hex string to block values
@@ -35,6 +37,11 @@ const (
 
 // NewBlockNumber creates a new BlockNumber instance.
 func NewBlockNumber(n *big.Int) BlockNumber {
+ if !n.IsInt64() {
+ // default to latest block if it overflows
+ return EthLatestBlockNumber
+ }
+
  return BlockNumber(n.Int64())
 }
 
@@ -176,10 +183,13 @@ func (bnh *BlockNumberOrHash) decodeFromString(input string) error {
  if err != nil {
  return err
  }
- if blockNumber > math.MaxInt64 {
- return fmt.Errorf("blocknumber %d is too high", blockNumber)
+
+ bnInt, err := ethermint.SafeInt64(blockNumber)
+ if err != nil {
+ return err
  }
- bn := BlockNumber(blockNumber)
+
+ bn := BlockNumber(bnInt)
  bnh.BlockNumber = &bn
  }
  return nil