From d1eacf93d434edd12d6998955cb88f3e3618094e Mon Sep 17 00:00:00 2001
From: Harley Laue <losinggeneration@gmail.com>
Date: Mon, 23 Apr 2018 14:27:51 -0700
Subject: [PATCH] Change implementation of find sub-tree to work with deep
 trees

* The previous implementation had an issue with nested structures deeper
  than one level. It would copy keys over instead of the expected object
  structure. In the example in this commit, UnmarshalKey("clothing") was
  returning "pants.size":"35" instead of "pants"{"size":"35"}
---
 viper.go      | 12 +++++++++---
 viper_test.go | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/viper.go b/viper.go
index 640a82c..572d676 100644
--- a/viper.go
+++ b/viper.go
@@ -1160,9 +1160,15 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) interface{} {
 	// it could also be a key prefix, search for that prefix to get the values from
 	// pflags that match it
 	sub := make(map[string]interface{})
-	for key, val := range v.pflags {
-		if flagDefault && strings.HasPrefix(key, lcaseKey) {
-			sub[strings.TrimPrefix(key, lcaseKey+".")] = val.ValueString()
+	for _, key := range v.AllKeys() {
+		if strings.HasPrefix(key, lcaseKey) {
+			value := v.Get(key)
+			keypath := strings.Split(lcaseKey, v.keyDelim)
+			path := strings.Split(key, v.keyDelim)[len(keypath)-1:]
+			lastKey := strings.ToLower(path[len(path)-1])
+			deepestMap := deepSearch(sub, path[1:len(path)-1])
+			// set innermost value
+			deepestMap[lastKey] = value
 		}
 	}
 	if len(sub) != 0 {
diff --git a/viper_test.go b/viper_test.go
index 16ff8fb..6834088 100644
--- a/viper_test.go
+++ b/viper_test.go
@@ -1327,7 +1327,49 @@ func TestSubPflags(t *testing.T) {
 	v.BindPFlag("eyes", &pflag.Flag{Value: newStringValue("brown"), Changed: true})
 	v.BindPFlag("beard", &pflag.Flag{Value: newStringValue("yes"), Changed: true})
 
+	type pants struct {
+		Size string
+	}
+
+	type clothing struct {
+		Jacket   string
+		Trousers string
+		Pants    pants
+	}
+
+	type cfg struct {
+		Name     string
+		Clothing clothing
+		Age      int
+		Eyes     string
+		Beard    bool
+	}
+
+	var c cfg
+	v.Unmarshal(&c)
+	assert.Equal(t, v.Get("name"), c.Name)
+	assert.Equal(t, v.Get("clothing.jacket"), c.Clothing.Jacket)
+	assert.Equal(t, v.Get("clothing.trousers"), c.Clothing.Trousers)
+	assert.Equal(t, v.Get("clothing.pants.size"), c.Clothing.Pants.Size)
+	assert.Equal(t, v.GetInt("age"), c.Age)
+	assert.Equal(t, v.Get("eyes"), c.Eyes)
+	assert.Equal(t, v.GetBool("beard"), c.Beard)
+
+	var cloth clothing
+	v.UnmarshalKey("clothing", &cloth)
+	assert.Equal(t, c.Clothing, cloth)
+
+	var p pants
+	v.UnmarshalKey("clothing.pants", &p)
+	assert.Equal(t, c.Clothing.Pants, p)
+
+	var size string
+	v.UnmarshalKey("clothing.pants.size", &size)
+	assert.Equal(t, c.Clothing.Pants.Size, size)
+
 	subv := v.Sub("clothing")
+	assert.Equal(t, v.Get("clothing.jacket"), subv.Get("jacket"))
+	assert.Equal(t, v.Get("clothing.trousers"), subv.Get("trousers"))
 	assert.Equal(t, v.Get("clothing.pants.size"), subv.Get("pants.size"))
 
 	subv = v.Sub("clothing.pants")