From 3ed364e92ae4c5a756349a48f0eba281ebe01180 Mon Sep 17 00:00:00 2001
From: Vladimir Mihailenco <vladimir.webdev@gmail.com>
Date: Fri, 22 Jan 2016 12:29:23 +0200
Subject: [PATCH] Sort can return nil reply. Fixes #246.

---
 commands.go      | 14 +++++++++--
 commands_test.go | 63 +++++++++++++++++++++++++++++++++++++++---------
 parser.go        |  7 ++++--
 3 files changed, 68 insertions(+), 16 deletions(-)

diff --git a/commands.go b/commands.go
index d6cb800d..f8a80f56 100644
--- a/commands.go
+++ b/commands.go
@@ -270,7 +270,7 @@ type Sort struct {
 	Store         string
 }
 
-func (c *commandable) Sort(key string, sort Sort) *StringSliceCmd {
+func (sort *Sort) args(key string) []interface{} {
 	args := []interface{}{"SORT", key}
 	if sort.By != "" {
 		args = append(args, "BY", sort.By)
@@ -290,7 +290,17 @@ func (c *commandable) Sort(key string, sort Sort) *StringSliceCmd {
 	if sort.Store != "" {
 		args = append(args, "STORE", sort.Store)
 	}
-	cmd := NewStringSliceCmd(args...)
+	return args
+}
+
+func (c *commandable) Sort(key string, sort Sort) *StringSliceCmd {
+	cmd := NewStringSliceCmd(sort.args(key)...)
+	c.Process(cmd)
+	return cmd
+}
+
+func (c *commandable) SortInterfaces(key string, sort Sort) *SliceCmd {
+	cmd := NewSliceCmd(sort.args(key)...)
 	c.Process(cmd)
 	return cmd
 }
diff --git a/commands_test.go b/commands_test.go
index f7d5502e..b82b0197 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -500,19 +500,58 @@ var _ = Describe("Commands", func() {
 		})
 
 		It("should Sort", func() {
-			lPush := client.LPush("list", "1")
-			Expect(lPush.Err()).NotTo(HaveOccurred())
-			Expect(lPush.Val()).To(Equal(int64(1)))
-			lPush = client.LPush("list", "3")
-			Expect(lPush.Err()).NotTo(HaveOccurred())
-			Expect(lPush.Val()).To(Equal(int64(2)))
-			lPush = client.LPush("list", "2")
-			Expect(lPush.Err()).NotTo(HaveOccurred())
-			Expect(lPush.Val()).To(Equal(int64(3)))
+			size, err := client.LPush("list", "1").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(1)))
 
-			sort := client.Sort("list", redis.Sort{Offset: 0, Count: 2, Order: "ASC"})
-			Expect(sort.Err()).NotTo(HaveOccurred())
-			Expect(sort.Val()).To(Equal([]string{"1", "2"}))
+			size, err = client.LPush("list", "3").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(2)))
+
+			size, err = client.LPush("list", "2").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(3)))
+
+			els, err := client.Sort("list", redis.Sort{
+				Offset: 0,
+				Count:  2,
+				Order:  "ASC",
+			}).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(els).To(Equal([]string{"1", "2"}))
+		})
+
+		It("should Sort and Get", func() {
+			size, err := client.LPush("list", "1").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(1)))
+
+			size, err = client.LPush("list", "3").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(2)))
+
+			size, err = client.LPush("list", "2").Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(size).To(Equal(int64(3)))
+
+			err = client.Set("object_2", "value2", 0).Err()
+			Expect(err).NotTo(HaveOccurred())
+
+			{
+				els, err := client.Sort("list", redis.Sort{
+					Get: []string{"object_*"},
+				}).Result()
+				Expect(err).NotTo(HaveOccurred())
+				Expect(els).To(Equal([]string{"", "value2", ""}))
+			}
+
+			{
+				els, err := client.SortInterfaces("list", redis.Sort{
+					Get: []string{"object_*"},
+				}).Result()
+				Expect(err).NotTo(HaveOccurred())
+				Expect(els).To(Equal([]interface{}{nil, "value2", nil}))
+			}
 		})
 
 		It("should TTL", func() {
diff --git a/parser.go b/parser.go
index 94fa5979..741c02a3 100644
--- a/parser.go
+++ b/parser.go
@@ -491,10 +491,13 @@ func stringSliceParser(cn *conn, n int64) (interface{}, error) {
 	ss := make([]string, 0, n)
 	for i := int64(0); i < n; i++ {
 		s, err := readStringReply(cn)
-		if err != nil {
+		if err == Nil {
+			ss = append(ss, "")
+		} else if err != nil {
 			return nil, err
+		} else {
+			ss = append(ss, s)
 		}
-		ss = append(ss, s)
 	}
 	return ss, nil
 }