make sure that OBJECT ENCODING returns skiplist for sorted sets, and not raw,...

make sure that OBJECT ENCODING returns skiplist for sorted sets, and not raw, so that once we will merge specially encoded sorted sets everything will make sense.

src/object.c

@@ -93,10 +93,13 @@ robj *createHashObject(void) {
 
 robj *createZsetObject(void) {
     zset *zs = zmalloc(sizeof(*zs));
+    robj *o;
 
     zs->dict = dictCreate(&zsetDictType,NULL);
     zs->zsl = zslCreate();
-    return createObject(REDIS_ZSET,zs);
+    o = createObject(REDIS_ZSET,zs);
+    o->encoding = REDIS_ENCODING_SKIPLIST;
+    return o;
 }
 
 void freeStringObject(robj *o) {
@@ -425,6 +428,7 @@ char *strEncoding(int encoding) {
     case REDIS_ENCODING_LINKEDLIST: return "linkedlist";
     case REDIS_ENCODING_ZIPLIST: return "ziplist";
     case REDIS_ENCODING_INTSET: return "intset";
+    case REDIS_ENCODING_SKIPLIST: return "skiplist";
     default: return "unknown";
     }
 }

src/redis.h

@@ -81,6 +81,7 @@
 #define REDIS_ENCODING_LINKEDLIST 4 /* Encoded as regular linked list */
 #define REDIS_ENCODING_ZIPLIST 5 /* Encoded as ziplist */
 #define REDIS_ENCODING_INTSET 6  /* Encoded as intset */
+#define REDIS_ENCODING_SKIPLIST 7  /* Encoded as skiplist */
 
 /* Object types only used for dumping to disk */
 #define REDIS_EXPIRETIME 253