Several optimizations:

* Use `yield from` wherever appropriate.
* Use SA's .one_or_none() where appropriate.

- Fix a bug in MailingList.pass_extensions.
- Use ValueError in other places for consistency.
- Remove unreached/nonsense code.
- Simplify the SubscriptionService.find_member() and .find_members()
  implementations.
- Boost coverage.

2 files changed, 17 insertions, 4 deletions

diff --git a/src/mailman/config/config.py b/src/mailman/config/config.py
index 69ddfb04f..424ad03c0 100644
--- a/src/mailman/config/config.py
+++ b/src/mailman/config/config.py
@@ -245,8 +245,7 @@ class Configuration:
     @property
     def runner_configs(self):
         """Iterate over all the runner configuration sections."""
-        for section in self._config.getByCategory('runner', []):
-            yield section
+        yield from self._config.getByCategory('runner', [])
 
     @property
     def archivers(self):
@@ -262,8 +261,7 @@ class Configuration:
     @property
     def language_configs(self):
         """Iterate over all the language configuration sections."""
-        for section in self._config.getByCategory('language', []):
-            yield section
+        yield from self._config.getByCategory('language', [])
 
 
 
diff --git a/src/mailman/config/tests/test_configuration.py b/src/mailman/config/tests/test_configuration.py
index 48cf21983..abbfce2c2 100644
--- a/src/mailman/config/tests/test_configuration.py
+++ b/src/mailman/config/tests/test_configuration.py
@@ -58,6 +58,21 @@ class TestConfiguration(unittest.TestCase):
                     pass
                 self.assertEqual(events, ['first', 'second', 'first'])
 
+    def test_config_template_dir_is_source(self):
+        fd, filename = tempfile.mkstemp()
+        self.addCleanup(os.remove, filename)
+        os.close(fd)
+        with open(filename, 'w') as fp:
+            print("""\
+[paths.here]
+template_dir: :source:
+""", file=fp)
+        config = Configuration()
+        config.load(filename)
+        import mailman.templates
+        self.assertEqual(config.TEMPLATE_DIR,
+                         os.path.dirname(mailman.templates.__file__))
+
 
 
 class TestExternal(unittest.TestCase):