From edc56495e150df241791bf5db02b83f66000686a Mon Sep 17 00:00:00 2001
From: Anonymous <anonymous@github.com>
Date: Fri, 9 Jul 2021 15:10:03 +0100
Subject: [PATCH] Fix possible panic when using ComposeDecodeHookFunc() with no
 funcs

---
 decode_hooks.go      |  5 +++++
 decode_hooks_test.go | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/decode_hooks.go b/decode_hooks.go
index 92e6f76f..5d871df1 100644
--- a/decode_hooks.go
+++ b/decode_hooks.go
@@ -63,6 +63,11 @@ func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc {
 	return func(f reflect.Value, t reflect.Value) (interface{}, error) {
 		var err error
 		var data interface{}
+
+		if len(fs) == 0 {
+			data = f.Interface()
+		}
+
 		newFrom := f
 		for _, f1 := range fs {
 			data, err = DecodeHookExec(f1, newFrom, t)
diff --git a/decode_hooks_test.go b/decode_hooks_test.go
index b3165bc9..cfa3c180 100644
--- a/decode_hooks_test.go
+++ b/decode_hooks_test.go
@@ -84,6 +84,38 @@ func TestComposeDecodeHookFunc_kinds(t *testing.T) {
 	}
 }
 
+func TestComposeDecodeHookFunc_safe_nofuncs(t *testing.T) {
+	f := ComposeDecodeHookFunc()
+	type myStruct2 struct {
+		MyInt int
+	}
+
+	type myStruct1 struct {
+		Blah map[string]myStruct2
+	}
+
+	src := &myStruct1{Blah: map[string]myStruct2{
+		"test": {
+			MyInt: 1,
+		},
+	}}
+
+	dst := &myStruct1{}
+	dConf := &DecoderConfig{
+		Result:      dst,
+		ErrorUnused: true,
+		DecodeHook:  f,
+	}
+	d, err := NewDecoder(dConf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	err = d.Decode(src)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
 func TestStringToSliceHookFunc(t *testing.T) {
 	f := StringToSliceHookFunc(",")