Fix for issue 566, fixed in a more long term way into the 2.4 branch

src/sort.c

@@ -363,6 +363,7 @@ void sortCommand(redisClient *c) {
                 }
             }
         }
+        lookupKeyWrite(c->db,storekey); /* Force expire of old key if needed. */
         dbReplace(c->db,storekey,sobj);
         /* Note: we add 1 because the DB is dirty anyway since even if the
          * SORT result is empty a new key is set and maybe the old content

src/t_string.c

@@ -25,6 +25,7 @@ void setGenericCommand(redisClient *c, int nx, robj *key, robj *val, robj *expir
         }
     }
 
+    lookupKeyWrite(c->db,key); /* Force expire of old key if needed */
     retval = dbAdd(c->db,key,val);
     if (retval == REDIS_ERR) {
         if (!nx) {