Document mostly dead code in RPOPLPUSH implementation.

diff --git a/src/t_list.c b/src/t_list.c
index 6a16a63201921028c4b13014d8039238d1be599c..ca03916b953fd1eb91d9e80b506b6646d97e45f4 100644 (file)
--- a/src/t_list.c
+++ b/src/t_list.c
@@ -699,6 +699,8 @@ void rpoplpushCommand(redisClient *c) {
         checkType(c,sobj,REDIS_LIST)) return;
 
     if (listTypeLength(sobj) == 0) {
+        /* This may only happen after loading very old RDB files. Recent
+         * versions of Redis delete keys of empty lists. */
         addReply(c,shared.nullbulk);
     } else {
         robj *dobj = lookupKeyWrite(c->db,c->argv[2]);