From 0cb8e1a348b4877bff4648d59a75b793a0664b41 Mon Sep 17 00:00:00 2001
From: Muhamad Azmy <muhamad.azmy@codescalers.com>
Date: Tue, 20 Jun 2017 01:59:48 +0200
Subject: [PATCH] Fix TTL issue in RPOPLPUSH command family (#304)

---
 server/cmd_list.go      | 29 +++++++++++++++++++++++++++++
 server/cmd_list_test.go | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/server/cmd_list.go b/server/cmd_list.go
index 7b0da6b..0acf52f 100644
--- a/server/cmd_list.go
+++ b/server/cmd_list.go
@@ -4,6 +4,7 @@ import (
 	"strconv"
 	"time"
 
+	"bytes"
 	"github.com/siddontang/go/hack"
 	"github.com/siddontang/ledisdb/ledis"
 )
@@ -285,6 +286,15 @@ func brpoplpushCommand(c *client) error {
 		return err
 	}
 
+	var ttl int64 = -1
+	if bytes.Compare(source, dest) == 0 {
+		var err error
+		ttl, err = c.db.LTTL(source)
+		if err != nil {
+			return err
+		}
+	}
+
 	ay, err := c.db.BRPop([][]byte{source}, timeout)
 	if err != nil {
 		return err
@@ -305,6 +315,11 @@ func brpoplpushCommand(c *client) error {
 		return err
 	}
 
+	//reset ttl
+	if ttl != -1 {
+		c.db.LExpire(source, ttl)
+	}
+
 	c.resp.writeBulk(data)
 	return nil
 
@@ -336,6 +351,15 @@ func rpoplpushCommand(c *client) error {
 	}
 	source, dest := args[0], args[1]
 
+	var ttl int64 = -1
+	if bytes.Compare(source, dest) == 0 {
+		var err error
+		ttl, err = c.db.LTTL(source)
+		if err != nil {
+			return err
+		}
+	}
+
 	data, err := c.db.RPop(source)
 	if err != nil {
 		return err
@@ -351,6 +375,11 @@ func rpoplpushCommand(c *client) error {
 		return err
 	}
 
+	//reset ttl
+	if ttl != -1 {
+		c.db.LExpire(source, ttl)
+	}
+
 	c.resp.writeBulk(data)
 	return nil
 }
diff --git a/server/cmd_list_test.go b/server/cmd_list_test.go
index c9bef53..12f0b8a 100644
--- a/server/cmd_list_test.go
+++ b/server/cmd_list_test.go
@@ -304,6 +304,9 @@ func TestRPopLPush(t *testing.T) {
 	src := []byte("sr")
 	des := []byte("de")
 
+	c.Do("lclear", src)
+	c.Do("lclear", des)
+
 	if _, err := goredis.Int(c.Do("rpoplpush", src, des)); err != goredis.ErrNil {
 		t.Fatal(err)
 	}
@@ -363,6 +366,36 @@ func TestRPopLPush(t *testing.T) {
 	}
 }
 
+func TestRPopLPushSingleElement(t *testing.T) {
+	c := getTestConn()
+	defer c.Close()
+
+	src := []byte("sr")
+
+	c.Do("lclear", src)
+	if n, err := goredis.Int(c.Do("rpush", src, 1)); err != nil {
+		t.Fatal(err)
+	} else if n != 1 {
+		t.Fatal(n)
+	}
+	ttl := 300
+	if _, err := c.Do("lexpire", src, ttl); err != nil {
+		t.Fatal(err)
+	}
+
+	if v, err := goredis.Int(c.Do("rpoplpush", src, src)); err != nil {
+		t.Fatal(err)
+	} else if v != 1 {
+		t.Fatal(v)
+	}
+
+	if tl, err := goredis.Int(c.Do("lttl", src)); err != nil {
+		t.Fatal(err)
+	} else if tl == -1 || tl > ttl {
+		t.Fatal(tl)
+	}
+}
+
 func TestTrim(t *testing.T) {
 	c := getTestConn()
 	defer c.Close()