update redbench

vendor/github.com/tidwall/redbench/README.md

@@ -4,8 +4,9 @@
 Redbench is a Go package that allows for bootstrapping benchmarks
 for servers using a custom implementation of the Redis protocol. It provides
 the same inputs and outputs as the
-[redis-benchmark](https://redis.io/topics/benchmarks) tool. The purpose of
-this library is to provide benchmarking for 
+[redis-benchmark](https://redis.io/topics/benchmarks) tool. 
+
+The purpose of this library is to provide benchmarking for 
 [Redcon](https://github.com/tidwall/redcon) compatible servers such as
 [Tile38](https://github.com/tidwall/tile38), but also works well for Redis
 operations that are not covered by the `redis-benchmark` tool such as the 
@@ -65,12 +66,14 @@ func main() {
 }
 ```
 
-The operations is like as executing, but without the `GEO*` commands.
+Which is similar to executing:
 
 ```
 $ redis-benchmark -t PING,SET,GET
 ```
 
+For a more complete example, check out [tile38-benchmark](https://github.com/tidwall/tile38/blob/master/cmd/tile38-benchmark/main.go) from the [Tile38](https://github.com/tidwall/tile38) project.
+
 ### Custom Options
 
 ```go

vendor/github.com/tidwall/redbench/bench.go

@@ -30,8 +30,10 @@ func readResp(rd *bufio.Reader, n int) error {
 			if err != nil {
 				return err
 			}
-			if _, err = io.CopyN(ioutil.Discard, rd, n+2); err != nil {
-				return err
+			if n >= 0 {
+				if _, err = io.CopyN(ioutil.Discard, rd, n+2); err != nil {
+					return err
+				}
 			}
 		case '*':
 			n, err := strconv.ParseInt(string(line[1:len(line)-2]), 10, 64)