runtime/internal/lib/reflect: fix Field closure kind to func

_demo/go/reflectfunc/reflectfunc.go

@@ -39,4 +39,12 @@ func main() {
 			panic(fmt.Sprintf("not func: %T", fn))
 		}
 	}
+	v := reflect.ValueOf(T{})
+	if v.Field(0).Kind() != reflect.Func {
+		panic("must func")
+	}
+}
+
+type T struct {
+	fn func(int)
 }

runtime/internal/lib/reflect/value.go

@@ -600,8 +600,13 @@ func (v Value) Field(i int) Value {
 	field := &tt.Fields[i]
 	typ := field.Typ
 
+	// Check closure to func
+	kind := typ.Kind()
+	if typ.IsClosure() {
+		kind = abi.Func
+	}
 	// Inherit permission bits from v, but clear flagEmbedRO.
-	fl := v.flag&(flagStickyRO|flagIndir|flagAddr) | flag(typ.Kind())
+	fl := v.flag&(flagStickyRO|flagIndir|flagAddr) | flag(kind)
 	// Using an unexported field forces flagRO.
 	if !field.Exported() {
 		if field.Embedded() {