Fix patch provided in #6554.

src/blocked.c

@@ -262,6 +262,13 @@ void handleClientsBlockedOnKeys(void) {
              * we can safely call signalKeyAsReady() against this key. */
             dictDelete(rl->db->ready_keys,rl->key);
 
+            /* Even if we are not inside call(), increment the call depth
+             * in order to make sure that keys are expired against a fixed
+             * reference time, and not against the wallclock time. This
+             * way we can lookup an object multiple times (BRPOPLPUSH does
+             * that) without the risk of it being freed in the second
+             * lookup, invalidating the first one.
+             * See https://github.com/antirez/redis/pull/6554. */
             server.call_depth++;
             updateCachedTime(0);
 
@@ -461,7 +468,7 @@ void handleClientsBlockedOnKeys(void) {
                 }
             }
 
-            server.call_depth++;
+            server.call_depth--;
 
             /* Free this item. */
             decrRefCount(rl->key);