Fixed #27882 -- Allowed {% cache %} to cache indefinitely.

1 files changed, 5 insertions, 4 deletions

diff --git a/django/templatetags/cache.py b/django/templatetags/cache.py
index 3af6dc4df6..9e402a1206 100644
--- a/django/templatetags/cache.py
+++ b/django/templatetags/cache.py
@@ -20,10 +20,11 @@ class CacheNode(Node):
             expire_time = self.expire_time_var.resolve(context)
         except VariableDoesNotExist:
             raise TemplateSyntaxError('"cache" tag got an unknown variable: %r' % self.expire_time_var.var)
-        try:
-            expire_time = int(expire_time)
-        except (ValueError, TypeError):
-            raise TemplateSyntaxError('"cache" tag got a non-integer timeout value: %r' % expire_time)
+        if expire_time is not None:
+            try:
+                expire_time = int(expire_time)
+            except (ValueError, TypeError):
+                raise TemplateSyntaxError('"cache" tag got a non-integer timeout value: %r' % expire_time)
         if self.cache_name:
             try:
                 cache_name = self.cache_name.resolve(context)