Fixed #22085 -- Added a feature for setting non-expiring keys as the default.

This feature allows the default `TIMEOUT` Cache argument to be set to `None`,
so that cache instances can set a non-expiring key as the default,
instead of using the default value of 5 minutes.

Previously, this was possible only by passing `None` as an argument to
the set() method of objects of type `BaseCache` (and subtypes).

1 files changed, 5 insertions, 4 deletions

diff --git a/django/core/cache/backends/base.py b/django/core/cache/backends/base.py
index ae83865db8..4b7806fc29 100644
--- a/django/core/cache/backends/base.py
+++ b/django/core/cache/backends/base.py
@@ -52,10 +52,11 @@ def get_key_func(key_func):
 class BaseCache(object):
     def __init__(self, params):
         timeout = params.get('timeout', params.get('TIMEOUT', 300))
-        try:
-            timeout = int(timeout)
-        except (ValueError, TypeError):
-            timeout = 300
+        if timeout is not None:
+            try:
+                timeout = int(timeout)
+            except (ValueError, TypeError):
+                timeout = 300
         self.default_timeout = timeout
 
         options = params.get('OPTIONS', {})