Issue #12599: Be more strict in accepting None vs. a false-like object
in importlib.
Thanks to PJE for pointing out the issue and Nick Coghlan for filing
the bug.
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 983abd5..415c488 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -217,7 +217,7 @@
"""
def module_for_loader_wrapper(self, fullname, *args, **kwargs):
module = sys.modules.get(fullname)
- is_reload = bool(module)
+ is_reload = module is not None
if not is_reload:
# This must be done before open() is called as the 'io' module
# implicitly imports 'locale' and would otherwise trigger an
@@ -711,7 +711,7 @@
If 'hooks' is false then use sys.path_hooks.
"""
- if not hooks:
+ if hooks is None:
hooks = sys.path_hooks
for hook in hooks:
try:
@@ -753,7 +753,7 @@
def find_module(cls, fullname, path=None):
"""Find the module on sys.path or 'path' based on sys.path_hooks and
sys.path_importer_cache."""
- if not path:
+ if path is None:
path = sys.path
for entry in path:
try:
diff --git a/Lib/importlib/test/import_/test_path.py b/Lib/importlib/test/import_/test_path.py
index a211bdf..fe47717 100644
--- a/Lib/importlib/test/import_/test_path.py
+++ b/Lib/importlib/test/import_/test_path.py
@@ -42,6 +42,15 @@
loader = machinery.PathFinder.find_module(module, [path])
self.assertTrue(loader is importer)
+ def test_empty_list(self):
+ # An empty list should not count as asking for sys.path.
+ module = 'module'
+ path = '<test path>'
+ importer = util.mock_modules(module)
+ with util.import_state(path_importer_cache={path: importer},
+ path=[path]):
+ self.assertIsNone(machinery.PathFinder.find_module('module', []))
+
def test_path_hooks(self):
# Test that sys.path_hooks is used.
# Test that sys.path_importer_cache is set.
diff --git a/Lib/importlib/test/test_util.py b/Lib/importlib/test/test_util.py
index c7cdad1..b035d65 100644
--- a/Lib/importlib/test/test_util.py
+++ b/Lib/importlib/test/test_util.py
@@ -65,8 +65,22 @@
self.assertEqual(wrapped.__name__, fxn.__name__)
self.assertEqual(wrapped.__qualname__, fxn.__qualname__)
-class SetPackageTests(unittest.TestCase):
+ def test_false_module(self):
+ # If for some odd reason a module is considered false, still return it
+ # from sys.modules.
+ class FalseModule(types.ModuleType):
+ def __bool__(self): return False
+ name = 'mod'
+ module = FalseModule(name)
+ with test_util.uncache(name):
+ self.assertFalse(module)
+ sys.modules[name] = module
+ given = self.return_module(name)
+ self.assertTrue(given is module)
+
+
+class SetPackageTests(unittest.TestCase):
"""Tests for importlib.util.set_package."""
diff --git a/Misc/NEWS b/Misc/NEWS
index 9f0009f..5c0c1c6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
Core and Builtins
-----------------
+- Issue #12599: Be more strict in accepting None compared to a false-like
+ object for importlib.util.module_for_loader and
+ importlib.machinery.PathFinder.
+
- Issue #14592: Attempting a relative import w/o __package__ or __name__ set in
globals raises a KeyError.
diff --git a/Python/importlib.h b/Python/importlib.h
index 3a03c46..392b941 100644
--- a/Python/importlib.h
+++ b/Python/importlib.h
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