Issue #28847: dbm.dumb now supports reading read-only files and no longer

writes the index file when it is not changed.

1 files changed, 16 insertions, 0 deletions

diff --git a/Lib/test/test_dbm_dumb.py b/Lib/test/test_dbm_dumb.py
index ff63c88..235ab11 100644
--- a/Lib/test/test_dbm_dumb.py
+++ b/Lib/test/test_dbm_dumb.py
@@ -5,6 +5,7 @@
 import io
 import operator
 import os
+import stat
 import unittest
 import dbm.dumb as dumbdbm
 from test import support
@@ -234,6 +235,21 @@ class DumbDBMTestCase(unittest.TestCase):
                     pass
             self.assertEqual(stdout.getvalue(), '')
 
+    @unittest.skipUnless(hasattr(os, 'chmod'), 'test needs os.chmod()')
+    def test_readonly_files(self):
+        with support.temp_dir() as dir:
+            fname = os.path.join(dir, 'db')
+            with dumbdbm.open(fname, 'n') as f:
+                self.assertEqual(list(f.keys()), [])
+                for key in self._dict:
+                    f[key] = self._dict[key]
+            os.chmod(fname + ".dir", stat.S_IRUSR)
+            os.chmod(fname + ".dat", stat.S_IRUSR)
+            os.chmod(dir, stat.S_IRUSR|stat.S_IXUSR)
+            with dumbdbm.open(fname, 'r') as f:
+                self.assertEqual(sorted(f.keys()), sorted(self._dict))
+                f.close()  # don't write
+
     def tearDown(self):
         _delete_files()