- Fix crash when the environment variable `PYTHONOPTIMIZED` is set to `2`

5 files changed, 20 insertions, 0 deletions

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 4f292f0..fa64e1a 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -24,6 +24,7 @@ jobs:
         - ["3.8",   "py38"]
         - ["3.9",   "py39"]
         - ["3.10",  "py310"]
+        - ["3.10", "py310-optimized"]
         - ["3.11",  "py311"]
         - ["pypy-2.7", "pypy"]
         - ["pypy-3.7", "pypy3"]
diff --git a/CHANGES.rst b/CHANGES.rst
index 479509c..40bf792 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -6,6 +6,10 @@
 5.1.0 (unreleased)
 ==================
 
+- Fix crash when the environment variable `PYTHONOPTIMIZED` is set to `2`
+  and docstrings are set to `None` by the interpreter.
+  (`#67 <https://github.com/zopefoundation/zope.component/issues/67>`_)
+
 - Add support for Python 3.10 and 3.11.
 
 
diff --git a/src/zope/component/interfaces.py b/src/zope/component/interfaces.py
index 068c625..0029a59 100644
--- a/src/zope/component/interfaces.py
+++ b/src/zope/component/interfaces.py
@@ -364,6 +364,12 @@ class IFactory(Interface):
 
 def _inherits_docs(func, iface):
     doc = iface[func.__name__].__doc__
+
+    # doc can be None if the interpreter drops all docstrings when the
+    # environment variable PYTHONOPTIMIZE is set 2.
+    if not doc:
+        return func
+
     # By adding the ..seealso:: we get a link from our overview page
     # to the specific narrative place where the function is described, because
     # our overview page uses :noindex:
diff --git a/src/zope/component/tests/test_interface.py b/src/zope/component/tests/test_interface.py
index f7d266a..ab56160 100644
--- a/src/zope/component/tests/test_interface.py
+++ b/src/zope/component/tests/test_interface.py
@@ -13,8 +13,14 @@
 ##############################################################################
 """Tests for z.c.interface
 """
+import os
 import unittest
 
+
+DOCSTRINGS_REMOVED = False
+if str(os.environ.get('PYTHONOPTIMIZE')) == '2':
+    DOCSTRINGS_REMOVED = True
+
 # pylint:disable=inherit-non-class,blacklisted-name
 
 class Test_provideInterface(unittest.TestCase):
@@ -346,6 +352,8 @@ class Test_searchInterfaceUtilities(unittest.TestCase):
         self.assertEqual(self._callFUT(object(), base=IFoo), [('foo', IFoo)])
 
 
+@unittest.skipIf(DOCSTRINGS_REMOVED,
+                 'Skipping tests, docstrings are optimized away')
 class Test_getInterfaceAllDocs(unittest.TestCase):
 
     def _callFUT(self, *args, **kw):
diff --git a/tox.ini b/tox.ini
index acba41b..9f551be 100644
--- a/tox.ini
+++ b/tox.ini
@@ -35,6 +35,7 @@ commands =
 setenv =
     ZOPE_INTERFACE_STRICT_IRO = 1
     pure: PURE_PYTHON = 1
+    optimized: PYTHONOPTIMIZE = 2
 
 [testenv:docs]
 basepython =