Attempting to compact a slice panics

[b1naryth1ef]

Trying to run the following code:

package main

import "github.com/vmihailenco/msgpack"
import "fmt"
import "unsafe"
import "reflect"

type Test struct {
    A uint16
    B uint16
    C string
    D [4]string
    E [2]int64
}

func main() {
    test := Test{
        A: uint16(1),
        B: uint16(25565),
        C: "yolotest",
        D: [4]string{"a", "b", "c", "d"},
        E: [2]int64{int64(1348293849324), int64(4345345345)},
    }
    buf, err := msgpack.Marshal(test)
    if err != nil {
        fmt.Printf("%s\n", err)
    }
    fmt.Printf("%s\n", buf)
    fmt.Printf("%s\n", len(buf))
    fmt.Printf("%s\n", unsafe.Sizeof(test))

    newzy := Test{}
    msgpack.Unmarshal(buf, &newzy)
    fmt.Printf("%s\n", newzy)
    fmt.Printf("%s\n", unsafe.Sizeof(newzy))
}

I get the following error:

panic: reflect: call of reflect.Value.IsNil on array Value

goroutine 1 [running]:
reflect.Value.IsNil(0x46ca98, 0xf840000e18, 0x112, 0x4aa070, 0x46ca98, ...)
    /usr/lib/go/src/pkg/reflect/value.go:895 +0x130
github.com/vmihailenco/msgpack.(*Encoder).encodeSlice(0xf84002f220, 0x46ca98, 0xf840000e18, 0x112, 0x1, ...)

This happens both when trying to compact a struct, and a single slice like:

func main() {
    test := [4]string{"a", "b", "c", "d"}
    buf, err := msgpack.Marshal(test)
    fmt.Printf("err: %s\n", err)
    newzy := make([]string, 4)
    msgpack.Unmarshal(buf, &newzy)
    fmt.Printf("V: %s\n", newzy)
}

If one was to comment the invalid IsNil call, you get the following error:

panic: interface conversion: interface is [4]string, not []string

goroutine 1 [running]:
github.com/vmihailenco/msgpack.(*Encoder).encodeSlice(0xf84002f220, 0x46ca98, 0xf840000e18, 0x112, 0x1, ...)

[vmihailenco]

Fixed. You probably need to read this http://blog.golang.org/slices , because [4]string is an array, not a slice.

[b1naryth1ef]

TIL. Thanks for the patch! 👍