`Retry()`: Support negative `retries` value (#2110)

* Support negative `retries` value

* Add unit test

* Add unittest for blocking api

1 files changed, 2 insertions, 1 deletions

diff --git a/redis/retry.py b/redis/retry.py
index 3dced35..57be971 100644
--- a/redis/retry.py
+++ b/redis/retry.py
@@ -16,6 +16,7 @@ class Retry:
         """
         Initialize a `Retry` object with a `Backoff` object
         that retries a maximum of `retries` times.
+        `retries` can be negative to retry forever.
         You can specify the types of supported errors which trigger
         a retry with the `supported_errors` parameter.
         """
@@ -46,7 +47,7 @@ class Retry:
             except self._supported_errors as error:
                 failures += 1
                 fail(error)
-                if failures > self._retries:
+                if self._retries >= 0 and failures > self._retries:
                     raise error
                 backoff = self._backoff.compute(failures)
                 if backoff > 0: