mcache.Free(data) panic, when the data is an empty slice

[CGongsz]

Operating System

macos

Go Version

go 1.22.1

Package Version

all version

Affected Packages

protobuf/grpc_compress.go

Expected Behavior

returned normally

Actual Behavior

panic index out of range [-1]

Reproduction Steps

1、Define the empty reponse
message XXXRes { }
2、Write an arbitrary compressor and register it （encoding.RegisterCompressor(compressor)）
3、Triggering the request
4、When the request returns，have a panic，'index out of range [-1]'

Other Information

mcache.Free

func Free(buf []byte) {
size := cap(buf)
if !isPowerOfTwo(size) {
return
}
buf = buf[:0]
caches[bsr(size)].Put(buf)
}
when size = 0，bsr(size) return -1

caches[-1] = nil

[CGongsz]

The fields in the response body are all default values, 'buf' will always be an empty slice