Fixed #26694 -- Made FileBasedCache.get() reraise non-ENOENT IOErrors.

django/core/cache/backends/filebased.py

@@ -40,8 +40,8 @@ class FileBasedCache(BaseCache):
                 if not self._is_expired(f):
                     return pickle.loads(zlib.decompress(f.read()))
         except IOError as e:
-            if e.errno == errno.ENOENT:
+            if e.errno != errno.ENOENT:
-                pass  # Cache file doesn't exist.
+                raise
         return default
 
     def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):

tests/cache/tests.py

@@ -5,6 +5,7 @@
 from __future__ import unicode_literals
 
 import copy
+import io
 import os
 import re
 import shutil
@@ -1261,6 +1262,17 @@ class FileBasedCacheTests(BaseCacheTests, TestCase):
         # This fails if not using the highest pickling protocol on Python 2.
         cache.set('unpicklable', UnpicklableType())
 
+    def test_get_ignores_enoent(self):
+        cache.set('foo', 'bar')
+        os.unlink(cache._key_to_file('foo'))
+        # Returns the default instead of erroring.
+        self.assertEqual(cache.get('foo', 'baz'), 'baz')
+
+    def test_get_does_not_ignore_non_enoent_errno_values(self):
+        with mock.patch.object(io, 'open', side_effect=IOError):
+            with self.assertRaises(IOError):
+                cache.get('foo')
+
 
 @override_settings(CACHES={
     'default': {