Fix xadd allow non negative maxlen (#2739)

* Fix xadd allow non negative maxlen

* Update change log

---------

Co-authored-by: dvora-h <[email protected]>

Author: aciddust

CHANGES

@@ -1,3 +1,4 @@
+    * Fix `xadd` command to accept non-negative `maxlen` including 0
     * Revert #2104, #2673, add `disconnect_on_error` option to `read_response()` (issues #2506, #2624)
     * Add `address_remap` parameter to `RedisCluster`
     * Fix incorrect usage of once flag in async Sentinel

redis/commands/core.py

@@ -3496,8 +3496,8 @@ def xadd(
             raise DataError("Only one of ```maxlen``` or ```minid``` may be specified")
 
         if maxlen is not None:
-            if not isinstance(maxlen, int) or maxlen < 1:
-                raise DataError("XADD maxlen must be a positive integer")
+            if not isinstance(maxlen, int) or maxlen < 0:
+                raise DataError("XADD maxlen must be non-negative integer")
             pieces.append(b"MAXLEN")
             if approximate:
                 pieces.append(b"~")