From 367cdc13945a489f834767a56024f1cce1f77f72 Mon Sep 17 00:00:00 2001
From: Chris Markiewicz <effigies@gmail.com>
Date: Sat, 23 Mar 2024 08:48:55 -0400
Subject: [PATCH 1/4] Add test for gh-117178

---
 Lib/test/test_importlib/test_lazy.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Lib/test/test_importlib/test_lazy.py b/Lib/test/test_importlib/test_lazy.py
index 38ab21907b58d9..a2a32e512cded1 100644
--- a/Lib/test/test_importlib/test_lazy.py
+++ b/Lib/test/test_importlib/test_lazy.py
@@ -178,6 +178,23 @@ def access_module():
             # Or multiple load attempts
             self.assertEqual(loader.load_count, 1)
 
+    def test_lazy_self_referential_modules(self):
+        # Directory modules with submodules that reference the parent can attempt to access
+        # the parent module during a load. Verify that this common pattern works with lazy loading.
+        # json is a good example in the stdlib.
+        json_modules = [name for name in sys.modules if name.startswith('json')]
+        with test_util.uncache(*json_modules):
+            # Standard lazy loading, unwrapped
+            spec = util.find_spec('json')
+            loader = util.LazyLoader(spec.loader)
+            spec.loader = loader
+            module = util.module_from_spec(spec)
+            sys.modules['json'] = module
+            loader.exec_module(module)
+
+            # Trigger load with attribute lookup
+            module.loads
+
 
 if __name__ == '__main__':
     unittest.main()

From fd630e77df46dd5b1e46b3d1f39ea0cf12ee9a5f Mon Sep 17 00:00:00 2001
From: Chris Markiewicz <effigies@gmail.com>
Date: Sat, 23 Mar 2024 08:53:50 -0400
Subject: [PATCH 2/4] fix gh-117178: Fall back to object.__getattribute__ for
 any reentrant lookups

---
 Lib/importlib/util.py | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py
index da9bd080a8dd5a..f1bb4b1fb41576 100644
--- a/Lib/importlib/util.py
+++ b/Lib/importlib/util.py
@@ -178,12 +178,11 @@ def __getattribute__(self, attr):
             # Only the first thread to get the lock should trigger the load
             # and reset the module's class. The rest can now getattr().
             if object.__getattribute__(self, '__class__') is _LazyModule:
-                # The first thread comes here multiple times as it descends the
-                # call stack. The first time, it sets is_loading and triggers
-                # exec_module(), which will access module.__dict__, module.__name__,
-                # and/or module.__spec__, reentering this method. These accesses
-                # need to be allowed to proceed without triggering the load again.
-                if loader_state['is_loading'] and attr.startswith('__') and attr.endswith('__'):
+                # Reentrant calls from the same thread must be allowed to proceed without
+                # triggering the load again.
+                # exec_module() and self-referential imports are the primary ways this can
+                # happen, but in any case we must return something to avoid deadlock.
+                if loader_state['is_loading']:
                     return object.__getattribute__(self, attr)
                 loader_state['is_loading'] = True
 

From 7da3f1bc1bc97a33e43083282545aa7ca03408c0 Mon Sep 17 00:00:00 2001
From: Chris Markiewicz <effigies@gmail.com>
Date: Sat, 23 Mar 2024 10:13:50 -0400
Subject: [PATCH 3/4] Update test_lazy_self_referential_modules to verify
 behavior of loaded function

---
 Lib/test/test_importlib/test_lazy.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_importlib/test_lazy.py b/Lib/test/test_importlib/test_lazy.py
index a2a32e512cded1..4d2cc4eb62b67c 100644
--- a/Lib/test/test_importlib/test_lazy.py
+++ b/Lib/test/test_importlib/test_lazy.py
@@ -192,8 +192,9 @@ def test_lazy_self_referential_modules(self):
             sys.modules['json'] = module
             loader.exec_module(module)
 
-            # Trigger load with attribute lookup
-            module.loads
+            # Trigger load with attribute lookup, ensure expected behavior
+            test_load = module.loads('{}')
+            self.assertEqual(test_load, {})
 
 
 if __name__ == '__main__':

From e5e6d655d4bccc076c919ec411b8cecbf6f6bc12 Mon Sep 17 00:00:00 2001
From: Chris Markiewicz <effigies@gmail.com>
Date: Sat, 23 Mar 2024 14:26:40 -0400
Subject: [PATCH 4/4] Add news blurb

---
 .../next/Library/2024-03-23-14-26-18.gh-issue-117178.vTisTG.rst | 2 ++
 1 file changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2024-03-23-14-26-18.gh-issue-117178.vTisTG.rst

diff --git a/Misc/NEWS.d/next/Library/2024-03-23-14-26-18.gh-issue-117178.vTisTG.rst b/Misc/NEWS.d/next/Library/2024-03-23-14-26-18.gh-issue-117178.vTisTG.rst
new file mode 100644
index 00000000000000..f9c53ebbfc3c96
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-03-23-14-26-18.gh-issue-117178.vTisTG.rst
@@ -0,0 +1,2 @@
+Fix regression in lazy loading of self-referential modules, introduced in
+gh-114781.