From afe03daed019e4c28be9a4019e5081d46f961a86 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 00:08:59 -0800
Subject: [PATCH 01/48] Refactor to reduce nesting

---
 Objects/moduleobject.c | 106 ++++++++++++++++++++---------------------
 1 file changed, 53 insertions(+), 53 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 3a1c516658dce7..e2cd42105406d3 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -819,68 +819,68 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         Py_DECREF(getattr);
         return result;
     }
+
+    if (suppress == 1) {
+        return NULL;
+    }
     if (PyDict_GetItemRef(m->md_dict, &_Py_ID(__name__), &mod_name) < 0) {
         return NULL;
     }
-    if (mod_name && PyUnicode_Check(mod_name)) {
-        PyObject *spec;
-        if (PyDict_GetItemRef(m->md_dict, &_Py_ID(__spec__), &spec) < 0) {
+    if (!mod_name || !PyUnicode_Check(mod_name)) {
+        Py_XDECREF(mod_name);
+        PyErr_Format(PyExc_AttributeError,
+                    "module has no attribute '%U'", name);
+        return NULL;
+    }
+    PyObject *spec;
+    if (PyDict_GetItemRef(m->md_dict, &_Py_ID(__spec__), &spec) < 0) {
+        Py_DECREF(mod_name);
+        return NULL;
+    }
+    int rc = _PyModuleSpec_IsInitializing(spec);
+    if (rc > 0) {
+        int valid_spec = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
+        if (valid_spec == -1) {
+            Py_XDECREF(spec);
             Py_DECREF(mod_name);
             return NULL;
         }
-        if (suppress != 1) {
-            int rc = _PyModuleSpec_IsInitializing(spec);
-            if (rc > 0) {
-                int valid_spec = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
-                if (valid_spec == -1) {
-                    Py_XDECREF(spec);
-                    Py_DECREF(mod_name);
-                    return NULL;
-                }
-                if (valid_spec == 1 && !PyUnicode_Check(origin)) {
-                    valid_spec = 0;
-                    Py_DECREF(origin);
-                }
-                if (valid_spec == 1) {
-                    PyErr_Format(PyExc_AttributeError,
-                                "partially initialized "
-                                "module '%U' from '%U' has no attribute '%U' "
-                                "(most likely due to a circular import)",
-                                mod_name, origin, name);
-                    Py_DECREF(origin);
-                }
-                else {
-                    PyErr_Format(PyExc_AttributeError,
-                                "partially initialized "
-                                "module '%U' has no attribute '%U' "
-                                "(most likely due to a circular import)",
-                                mod_name, name);
-                }
-            }
-            else if (rc == 0) {
-                rc = _PyModuleSpec_IsUninitializedSubmodule(spec, name);
-                if (rc > 0) {
-                    PyErr_Format(PyExc_AttributeError,
-                                "cannot access submodule '%U' of module '%U' "
-                                "(most likely due to a circular import)",
-                                name, mod_name);
-                }
-                else if (rc == 0) {
-                    PyErr_Format(PyExc_AttributeError,
-                                "module '%U' has no attribute '%U'",
-                                mod_name, name);
-                }
-            }
+        if (valid_spec == 1 && !PyUnicode_Check(origin)) {
+            valid_spec = 0;
+            Py_DECREF(origin);
+        }
+        if (valid_spec == 1) {
+            PyErr_Format(PyExc_AttributeError,
+                        "partially initialized "
+                        "module '%U' from '%U' has no attribute '%U' "
+                        "(most likely due to a circular import)",
+                        mod_name, origin, name);
+            Py_DECREF(origin);
+        }
+        else {
+            PyErr_Format(PyExc_AttributeError,
+                        "partially initialized "
+                        "module '%U' has no attribute '%U' "
+                        "(most likely due to a circular import)",
+                        mod_name, name);
         }
-        Py_XDECREF(spec);
-        Py_DECREF(mod_name);
-        return NULL;
     }
-    Py_XDECREF(mod_name);
-    if (suppress != 1) {
-        PyErr_Format(PyExc_AttributeError,
-                    "module has no attribute '%U'", name);
+    else if (rc == 0) {
+        rc = _PyModuleSpec_IsUninitializedSubmodule(spec, name);
+        if (rc > 0) {
+            PyErr_Format(PyExc_AttributeError,
+                        "cannot access submodule '%U' of module '%U' "
+                        "(most likely due to a circular import)",
+                        name, mod_name);
+        }
+        else if (rc == 0) {
+            PyErr_Format(PyExc_AttributeError,
+                        "module '%U' has no attribute '%U'",
+                        mod_name, name);
+        }
     }
+    Py_XDECREF(spec);
+    Py_DECREF(mod_name);
     return NULL;
 }
 

From ae438a4f81358a455cc38d6e20aa689d1a4188cc Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 00:20:10 -0800
Subject: [PATCH 02/48] Check for script shadowing stdlib

---
 Lib/test/test_import/__init__.py |  42 ++++++++++
 Objects/moduleobject.c           | 139 ++++++++++++++++++++++++-------
 2 files changed, 150 insertions(+), 31 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 7b0126226c4aba..56e2c68ade7d28 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -790,6 +790,48 @@ def test_issue105979(self):
         self.assertIn("Frozen object named 'x' is invalid",
                       str(cm.exception))
 
+    def test_cwd_script_shadowing_stdlib(self):
+        with CleanImport('collections'):
+            import collections
+            collections.__spec__ = types.SimpleNamespace()
+            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+            with self.assertRaisesRegex(
+                AttributeError,
+                r"module 'collections' has no attribute 'does_not_exist' \(most "
+                r"likely due to '.*collections.py' shadowing the standard "
+                r"library module named 'collections'\)"
+            ):
+                collections.does_not_exist
+
+    def test_shadowing_stdlib_edge_cases(self):
+        with CleanImport('collections'):
+            import collections
+            collections.__spec__ = types.SimpleNamespace()
+            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+            with CleanImport('sys'):
+                import sys
+                sys.stdlib_module_names = None
+                with self.assertRaisesRegex(
+                    AttributeError,
+                    r"module 'collections' has no attribute 'does_not_exist'"
+                ):
+                    collections.does_not_exist
+
+                del sys.stdlib_module_names
+                with self.assertRaisesRegex(
+                    AttributeError,
+                    r"module 'collections' has no attribute 'does_not_exist'"
+                ):
+                    collections.does_not_exist
+            with CleanImport("os"), CleanImport('os.path'):
+                import os as clean_os
+                del clean_os.path.dirname
+                with self.assertRaisesRegex(
+                    AttributeError,
+                    r"module '.*path' has no attribute 'dirname'"
+                ):
+                    collections.does_not_exist
+
 
 @skip_if_dont_write_bytecode
 class FilePermissionTests(unittest.TestCase):
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index e2cd42105406d3..38c6ba33641a73 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -788,7 +788,7 @@ PyObject*
 _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
 {
     // When suppress=1, this function suppresses AttributeError.
-    PyObject *attr, *mod_name, *getattr, *origin;
+    PyObject *attr, *mod_name, *getattr;
     attr = _PyObject_GenericGetAttrWithDict((PyObject *)m, name, NULL, suppress);
     if (attr) {
         return attr;
@@ -837,48 +837,125 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         Py_DECREF(mod_name);
         return NULL;
     }
-    int rc = _PyModuleSpec_IsInitializing(spec);
-    if (rc > 0) {
-        int valid_spec = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
-        if (valid_spec == -1) {
-            Py_XDECREF(spec);
+    PyObject *origin = NULL;
+    if (spec) {
+        int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
+        if (rc == -1) {
+            Py_DECREF(spec);
             Py_DECREF(mod_name);
             return NULL;
         }
-        if (valid_spec == 1 && !PyUnicode_Check(origin)) {
-            valid_spec = 0;
-            Py_DECREF(origin);
-        }
-        if (valid_spec == 1) {
-            PyErr_Format(PyExc_AttributeError,
-                        "partially initialized "
-                        "module '%U' from '%U' has no attribute '%U' "
-                        "(most likely due to a circular import)",
-                        mod_name, origin, name);
+        if (rc == 1 && !PyUnicode_Check(origin)) {
             Py_DECREF(origin);
+            origin = NULL;
         }
-        else {
-            PyErr_Format(PyExc_AttributeError,
-                        "partially initialized "
-                        "module '%U' has no attribute '%U' "
-                        "(most likely due to a circular import)",
-                        mod_name, name);
+    }
+
+    int is_script_shadowing_stdlib = 0;
+    // Check mod.__name__ in sys.stdlib_module_names
+    // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
+    PyObject *stdlib = NULL;
+    if (origin) {
+        // Checks against mod_name are to avoid bad recursion
+        if (
+            PyUnicode_CompareWithASCIIString(mod_name, "sys") != 0
+            && PyUnicode_CompareWithASCIIString(mod_name, "builtins") != 0
+        ) {
+            stdlib = _PyImport_GetModuleAttrString("sys", "stdlib_module_names");
+            if (!stdlib) {
+                if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
+                    PyErr_Clear();
+                } else {
+                    goto done;
+                }
+            }
+            if (stdlib && PyFrozenSet_Check(stdlib) && PySet_Contains(stdlib, mod_name)) {
+                if (
+                    PyUnicode_CompareWithASCIIString(mod_name, "os") != 0
+                    && PyUnicode_CompareWithASCIIString(mod_name, "posixpath") != 0
+                    && PyUnicode_CompareWithASCIIString(mod_name, "ntpath") != 0
+                ) {
+                    PyObject *os_path = _PyImport_GetModuleAttrString("os", "path");
+                    if (!os_path) {
+                        goto done;
+                    }
+                    PyObject *dirname = PyObject_GetAttrString(os_path, "dirname");
+                    Py_DECREF(os_path);
+                    if (!dirname) {
+                        goto done;
+                    }
+                    PyObject *origin_dir = _PyObject_CallOneArg(dirname, origin);
+                    Py_DECREF(dirname);
+                    if (!origin_dir) {
+                        goto done;
+                    }
+
+                    PyObject *getcwd = _PyImport_GetModuleAttrString("os", "getcwd");
+                    if (!getcwd) {
+                        Py_DECREF(origin_dir);
+                        goto done;
+                    }
+                    PyObject *cwd = _PyObject_CallNoArgs(getcwd);
+                    Py_DECREF(getcwd);
+                    if (!cwd) {
+                        Py_DECREF(origin_dir);
+                        goto done;
+                    }
+
+                    is_script_shadowing_stdlib = PyObject_RichCompareBool(origin_dir, cwd, Py_EQ);
+                    Py_DECREF(origin_dir);
+                    Py_DECREF(cwd);
+                    if (is_script_shadowing_stdlib < 0) {
+                        goto done;
+                    }
+                }
+            }
         }
     }
-    else if (rc == 0) {
-        rc = _PyModuleSpec_IsUninitializedSubmodule(spec, name);
+
+    if (is_script_shadowing_stdlib == 1) {
+        PyErr_Format(PyExc_AttributeError,
+                    "module '%U' has no attribute '%U' "
+                    "(most likely due to '%U' shadowing the standard library "
+                    "module named '%U')",
+                    mod_name, name, origin, mod_name);
+    } else {
+        int rc = _PyModuleSpec_IsInitializing(spec);
         if (rc > 0) {
-            PyErr_Format(PyExc_AttributeError,
-                        "cannot access submodule '%U' of module '%U' "
-                        "(most likely due to a circular import)",
-                        name, mod_name);
+            if (origin) {
+                PyErr_Format(PyExc_AttributeError,
+                            "partially initialized "
+                            "module '%U' from '%U' has no attribute '%U' "
+                            "(most likely due to a circular import)",
+                            mod_name, origin, name);
+            }
+            else {
+                PyErr_Format(PyExc_AttributeError,
+                            "partially initialized "
+                            "module '%U' has no attribute '%U' "
+                            "(most likely due to a circular import)",
+                            mod_name, name);
+            }
         }
         else if (rc == 0) {
-            PyErr_Format(PyExc_AttributeError,
-                        "module '%U' has no attribute '%U'",
-                        mod_name, name);
+            rc = _PyModuleSpec_IsUninitializedSubmodule(spec, name);
+            if (rc > 0) {
+                PyErr_Format(PyExc_AttributeError,
+                            "cannot access submodule '%U' of module '%U' "
+                            "(most likely due to a circular import)",
+                            name, mod_name);
+            }
+            else if (rc == 0) {
+                PyErr_Format(PyExc_AttributeError,
+                            "module '%U' has no attribute '%U'",
+                            mod_name, name);
+            }
         }
     }
+
+done:
+    Py_XDECREF(stdlib);
+    Py_XDECREF(origin);
     Py_XDECREF(spec);
     Py_DECREF(mod_name);
     return NULL;

From 0933591b580efd8cbb58463d061d5fb784424f67 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 01:58:51 -0800
Subject: [PATCH 03/48] Add What's New

---
 Doc/whatsnew/3.13.rst | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 3ab6d1ddc6ef21..622741202a4d0c 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -94,6 +94,24 @@ Improved Error Messages
   variables. See also :ref:`using-on-controlling-color`.
   (Contributed by Pablo Galindo Salgado in :gh:`112730`.)
 
+* A common mistake is to write a script with the same name as a
+  standard library module. The interpreter now detects this and
+  displays a more helpful error message.
+  (Contributed by Shantanu Jain in :gh:`95754`.)
+
+  .. code-block:: shell-session
+
+    $ python random.py
+    Traceback (most recent call last):
+      File "/home/random.py", line 1, in <module>
+        import random; print(random.randint(5))
+        ^^^^^^^^^^^^^
+      File "/home/random.py", line 1, in <module>
+        import random; print(random.randint(5))
+                            ^^^^^^^^^^^^^^
+    AttributeError: module 'random' has no attribute 'randint' (most likely due to '/home/random.py' shadowing the standard library module named 'random')
+
+
 Other Language Changes
 ======================
 

From 7f24b99b14452997cc90235c6cd364f393a0fe96 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 19:37:10 -0800
Subject: [PATCH 04/48] Avoid calling into Python

---
 Lib/test/test_import/__init__.py | 38 ++++---------
 Objects/moduleobject.c           | 98 ++++++++++++++------------------
 2 files changed, 55 insertions(+), 81 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 56e2c68ade7d28..11af07a4e7782b 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -803,34 +803,20 @@ def test_cwd_script_shadowing_stdlib(self):
             ):
                 collections.does_not_exist
 
-    def test_shadowing_stdlib_edge_cases(self):
         with CleanImport('collections'):
             import collections
-            collections.__spec__ = types.SimpleNamespace()
-            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
-            with CleanImport('sys'):
-                import sys
-                sys.stdlib_module_names = None
-                with self.assertRaisesRegex(
-                    AttributeError,
-                    r"module 'collections' has no attribute 'does_not_exist'"
-                ):
-                    collections.does_not_exist
-
-                del sys.stdlib_module_names
-                with self.assertRaisesRegex(
-                    AttributeError,
-                    r"module 'collections' has no attribute 'does_not_exist'"
-                ):
-                    collections.does_not_exist
-            with CleanImport("os"), CleanImport('os.path'):
-                import os as clean_os
-                del clean_os.path.dirname
-                with self.assertRaisesRegex(
-                    AttributeError,
-                    r"module '.*path' has no attribute 'dirname'"
-                ):
-                    collections.does_not_exist
+            del collections.__spec__.origin
+            with self.assertRaisesRegex(
+                AttributeError,
+                r"module 'collections' has no attribute 'does_not_exist'$"
+            ):
+                collections.does_not_exist
+            del collections.__spec__
+            with self.assertRaisesRegex(
+                AttributeError,
+                r"module 'collections' has no attribute 'does_not_exist'$"
+            ):
+                collections.does_not_exist
 
 
 @skip_if_dont_write_bytecode
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 38c6ba33641a73..ac28b7f4373f6c 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -3,6 +3,7 @@
 
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
+#include "pycore_fileutils.h"     // _Py_wgetcwd
 #include "pycore_interp.h"        // PyInterpreterState.importlib
 #include "pycore_modsupport.h"    // _PyModule_CreateInitialized()
 #include "pycore_moduleobject.h"  // _PyModule_GetDef()
@@ -10,6 +11,8 @@
 #include "pycore_pyerrors.h"      // _PyErr_FormatFromCause()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 
+#include "osdefs.h"               // MAXPATHLEN
+#include "Python/stdlib_module_names.h"  // _Py_stdlib_module_names
 
 
 static PyMemberDef module_members[] = {
@@ -784,6 +787,20 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
     return rc;
 }
 
+// TODO: deduplicate with suggestions.c. Where should this go?
+static bool
+is_name_stdlib_module(PyObject* name)
+{
+    const char* the_name = PyUnicode_AsUTF8(name);
+    Py_ssize_t len = Py_ARRAY_LENGTH(_Py_stdlib_module_names);
+    for (Py_ssize_t i = 0; i < len; i++) {
+        if (strcmp(the_name, _Py_stdlib_module_names[i]) == 0) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
 PyObject*
 _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
 {
@@ -854,62 +871,34 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     int is_script_shadowing_stdlib = 0;
     // Check mod.__name__ in sys.stdlib_module_names
     // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
-    PyObject *stdlib = NULL;
-    if (origin) {
-        // Checks against mod_name are to avoid bad recursion
-        if (
-            PyUnicode_CompareWithASCIIString(mod_name, "sys") != 0
-            && PyUnicode_CompareWithASCIIString(mod_name, "builtins") != 0
-        ) {
-            stdlib = _PyImport_GetModuleAttrString("sys", "stdlib_module_names");
-            if (!stdlib) {
-                if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
-                    PyErr_Clear();
-                } else {
-                    goto done;
-                }
+    if (origin && is_name_stdlib_module(mod_name)) {
+        wchar_t cwdbuf[MAXPATHLEN];
+        if(_Py_wgetcwd(cwdbuf, MAXPATHLEN)) {
+            PyObject *cwd = PyUnicode_FromWideChar(cwdbuf, wcslen(cwdbuf));
+            if (!cwd) {
+                goto done;
             }
-            if (stdlib && PyFrozenSet_Check(stdlib) && PySet_Contains(stdlib, mod_name)) {
-                if (
-                    PyUnicode_CompareWithASCIIString(mod_name, "os") != 0
-                    && PyUnicode_CompareWithASCIIString(mod_name, "posixpath") != 0
-                    && PyUnicode_CompareWithASCIIString(mod_name, "ntpath") != 0
-                ) {
-                    PyObject *os_path = _PyImport_GetModuleAttrString("os", "path");
-                    if (!os_path) {
-                        goto done;
-                    }
-                    PyObject *dirname = PyObject_GetAttrString(os_path, "dirname");
-                    Py_DECREF(os_path);
-                    if (!dirname) {
-                        goto done;
-                    }
-                    PyObject *origin_dir = _PyObject_CallOneArg(dirname, origin);
-                    Py_DECREF(dirname);
-                    if (!origin_dir) {
-                        goto done;
-                    }
-
-                    PyObject *getcwd = _PyImport_GetModuleAttrString("os", "getcwd");
-                    if (!getcwd) {
-                        Py_DECREF(origin_dir);
-                        goto done;
-                    }
-                    PyObject *cwd = _PyObject_CallNoArgs(getcwd);
-                    Py_DECREF(getcwd);
-                    if (!cwd) {
-                        Py_DECREF(origin_dir);
-                        goto done;
-                    }
-
-                    is_script_shadowing_stdlib = PyObject_RichCompareBool(origin_dir, cwd, Py_EQ);
-                    Py_DECREF(origin_dir);
-                    Py_DECREF(cwd);
-                    if (is_script_shadowing_stdlib < 0) {
-                        goto done;
-                    }
-                }
+            const char sep_char = SEP;
+            PyObject *sep = PyUnicode_FromStringAndSize(&sep_char, 1);
+            if (!sep) {
+                Py_DECREF(cwd);
+                goto done;
+            }
+            PyObject *parts = PyUnicode_RPartition(origin, sep);
+            Py_DECREF(sep);
+            if (!parts) {
+                Py_DECREF(cwd);
+                goto done;
+            }
+            int rc = PyUnicode_Compare(cwd, PyTuple_GET_ITEM(parts, 0));
+            if (rc == -1 && PyErr_Occurred()) {
+                Py_DECREF(parts);
+                Py_DECREF(cwd);
+                goto done;
             }
+            is_script_shadowing_stdlib = rc == 0;
+            Py_DECREF(parts);
+            Py_DECREF(cwd);
         }
     }
 
@@ -954,7 +943,6 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     }
 
 done:
-    Py_XDECREF(stdlib);
     Py_XDECREF(origin);
     Py_XDECREF(spec);
     Py_DECREF(mod_name);

From f073672f96271f24690b4ac45b4a7dce40662ddb Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Sun, 7 Jan 2024 03:38:38 +0000
Subject: [PATCH 05/48] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20b?=
 =?UTF-8?q?lurb=5Fit.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst                | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst b/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst
new file mode 100644
index 00000000000000..30800cb94418c1
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst	
@@ -0,0 +1 @@
+Improve the error message when a script in the current directory shadows a module from the standard library.

From 5e229685c9ec39ce20aeaa7921e4f6d5ea954cd3 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 19:55:35 -0800
Subject: [PATCH 06/48] just use wchar everywhere

---
 Objects/moduleobject.c | 36 +++++++++++-------------------------
 1 file changed, 11 insertions(+), 25 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index ac28b7f4373f6c..b1d8c108056d78 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -12,7 +12,7 @@
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 
 #include "osdefs.h"               // MAXPATHLEN
-#include "Python/stdlib_module_names.h"  // _Py_stdlib_module_names
+#include "../Python/stdlib_module_names.h"  // _Py_stdlib_module_names
 
 
 static PyMemberDef module_members[] = {
@@ -872,33 +872,19 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     // Check mod.__name__ in sys.stdlib_module_names
     // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
     if (origin && is_name_stdlib_module(mod_name)) {
-        wchar_t cwdbuf[MAXPATHLEN];
-        if(_Py_wgetcwd(cwdbuf, MAXPATHLEN)) {
-            PyObject *cwd = PyUnicode_FromWideChar(cwdbuf, wcslen(cwdbuf));
-            if (!cwd) {
+        wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
+        if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
+            int rc = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
+            if (rc < 0) {
                 goto done;
             }
-            const char sep_char = SEP;
-            PyObject *sep = PyUnicode_FromStringAndSize(&sep_char, 1);
-            if (!sep) {
-                Py_DECREF(cwd);
-                goto done;
-            }
-            PyObject *parts = PyUnicode_RPartition(origin, sep);
-            Py_DECREF(sep);
-            if (!parts) {
-                Py_DECREF(cwd);
-                goto done;
-            }
-            int rc = PyUnicode_Compare(cwd, PyTuple_GET_ITEM(parts, 0));
-            if (rc == -1 && PyErr_Occurred()) {
-                Py_DECREF(parts);
-                Py_DECREF(cwd);
-                goto done;
+            wchar_t *sep = wcsrchr(origin_dirname, SEP);
+            if (sep) {
+                *sep = L'\0';
+                if (wcscmp(cwd, origin_dirname) == 0) {
+                    is_script_shadowing_stdlib = 1;
+                }
             }
-            is_script_shadowing_stdlib = rc == 0;
-            Py_DECREF(parts);
-            Py_DECREF(cwd);
         }
     }
 

From 4db6e6cb52abac624c1b8f826ebf3a3767928763 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 6 Jan 2024 21:10:08 -0800
Subject: [PATCH 07/48] fix warning

---
 Objects/moduleobject.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index b1d8c108056d78..d6aed358ae0133 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -874,8 +874,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     if (origin && is_name_stdlib_module(mod_name)) {
         wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
         if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
-            int rc = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
-            if (rc < 0) {
+            if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
                 goto done;
             }
             wchar_t *sep = wcsrchr(origin_dirname, SEP);

From 2150dc538ce54a8cb5a02acdff80b19c9f28a4c4 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sun, 21 Jan 2024 15:41:01 -0800
Subject: [PATCH 08/48] do stdlib module name check via PySys

---
 Objects/moduleobject.c | 40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index d6aed358ae0133..7e9691dc487162 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -12,7 +12,6 @@
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
 
 #include "osdefs.h"               // MAXPATHLEN
-#include "../Python/stdlib_module_names.h"  // _Py_stdlib_module_names
 
 
 static PyMemberDef module_members[] = {
@@ -787,20 +786,6 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
     return rc;
 }
 
-// TODO: deduplicate with suggestions.c. Where should this go?
-static bool
-is_name_stdlib_module(PyObject* name)
-{
-    const char* the_name = PyUnicode_AsUTF8(name);
-    Py_ssize_t len = Py_ARRAY_LENGTH(_Py_stdlib_module_names);
-    for (Py_ssize_t i = 0; i < len; i++) {
-        if (strcmp(the_name, _Py_stdlib_module_names[i]) == 0) {
-            return 1;
-        }
-    }
-    return 0;
-}
-
 PyObject*
 _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
 {
@@ -871,17 +856,20 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     int is_script_shadowing_stdlib = 0;
     // Check mod.__name__ in sys.stdlib_module_names
     // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
-    if (origin && is_name_stdlib_module(mod_name)) {
-        wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
-        if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
-            if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
-                goto done;
-            }
-            wchar_t *sep = wcsrchr(origin_dirname, SEP);
-            if (sep) {
-                *sep = L'\0';
-                if (wcscmp(cwd, origin_dirname) == 0) {
-                    is_script_shadowing_stdlib = 1;
+    if (origin) {
+        PyObject *stdlib = PySys_GetObject("stdlib_module_names");
+        if (stdlib && PyAnySet_Check(stdlib) && PySet_Contains(stdlib, mod_name)) {
+            wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
+            if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
+                if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
+                    goto done;
+                }
+                wchar_t *sep = wcsrchr(origin_dirname, SEP);
+                if (sep) {
+                    *sep = L'\0';
+                    if (wcscmp(cwd, origin_dirname) == 0) {
+                        is_script_shadowing_stdlib = 1;
+                    }
                 }
             }
         }

From 0e1e3d8fd4225c356abd641353702bca166a60c9 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sun, 21 Jan 2024 16:05:13 -0800
Subject: [PATCH 09/48] add back test case

---
 Lib/test/test_import/__init__.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 11af07a4e7782b..735ad47fb4917f 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -795,6 +795,7 @@ def test_cwd_script_shadowing_stdlib(self):
             import collections
             collections.__spec__ = types.SimpleNamespace()
             collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+
             with self.assertRaisesRegex(
                 AttributeError,
                 r"module 'collections' has no attribute 'does_not_exist' \(most "
@@ -803,6 +804,28 @@ def test_cwd_script_shadowing_stdlib(self):
             ):
                 collections.does_not_exist
 
+    def test_shadowing_stdlib_edge_cases(self):
+        with CleanImport('collections'):
+            import collections
+            collections.__spec__ = types.SimpleNamespace()
+            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+
+            with CleanImport('sys'):
+                import sys
+                sys.stdlib_module_names = None
+                with self.assertRaisesRegex(
+                    AttributeError,
+                    r"module 'collections' has no attribute 'does_not_exist'"
+                ):
+                    collections.does_not_exist
+
+                del sys.stdlib_module_names
+                with self.assertRaisesRegex(
+                    AttributeError,
+                    r"module 'collections' has no attribute 'does_not_exist'"
+                ):
+                    collections.does_not_exist
+
         with CleanImport('collections'):
             import collections
             del collections.__spec__.origin

From 2486d002332e1ee557b2639f65427ef219c20ae1 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sun, 21 Jan 2024 16:44:21 -0800
Subject: [PATCH 10/48] CleanImport sys is not enough

---
 Lib/test/test_import/__init__.py | 51 +++++++++++++++++---------------
 1 file changed, 27 insertions(+), 24 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 735ad47fb4917f..49392ea6cbeffe 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -804,30 +804,6 @@ def test_cwd_script_shadowing_stdlib(self):
             ):
                 collections.does_not_exist
 
-    def test_shadowing_stdlib_edge_cases(self):
-        with CleanImport('collections'):
-            import collections
-            collections.__spec__ = types.SimpleNamespace()
-            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
-
-            with CleanImport('sys'):
-                import sys
-                sys.stdlib_module_names = None
-                with self.assertRaisesRegex(
-                    AttributeError,
-                    r"module 'collections' has no attribute 'does_not_exist'"
-                ):
-                    collections.does_not_exist
-
-                del sys.stdlib_module_names
-                with self.assertRaisesRegex(
-                    AttributeError,
-                    r"module 'collections' has no attribute 'does_not_exist'"
-                ):
-                    collections.does_not_exist
-
-        with CleanImport('collections'):
-            import collections
             del collections.__spec__.origin
             with self.assertRaisesRegex(
                 AttributeError,
@@ -841,6 +817,33 @@ def test_shadowing_stdlib_edge_cases(self):
             ):
                 collections.does_not_exist
 
+    def test_shadowing_stdlib_sys_edge_cases(self):
+        program = textwrap.dedent('''
+import collections
+import os
+import types
+collections.__spec__ = types.SimpleNamespace()
+collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+import sys
+sys.stdlib_module_names = None
+try:
+    collections.does_not_exist
+except AttributeError as e:
+    print(str(e))
+
+del sys.stdlib_module_names
+try:
+    collections.does_not_exist
+except AttributeError as e:
+    print(str(e))
+''')
+        popen = script_helper.spawn_python('-c', program)
+        stdout, stderr = popen.communicate()
+        self.assertEqual(stdout.splitlines(), [
+            b"module 'collections' has no attribute 'does_not_exist'",
+            b"module 'collections' has no attribute 'does_not_exist'",
+        ])
+
 
 @skip_if_dont_write_bytecode
 class FilePermissionTests(unittest.TestCase):

From 9f0955d8262f9203b9012834b7ff8e278d2b0a20 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 22 Jan 2024 00:45:46 -0800
Subject: [PATCH 11/48] handle set error

---
 Objects/moduleobject.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 7e9691dc487162..2f32f30232cb6a 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -858,20 +858,26 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
     if (origin) {
         PyObject *stdlib = PySys_GetObject("stdlib_module_names");
-        if (stdlib && PyAnySet_Check(stdlib) && PySet_Contains(stdlib, mod_name)) {
-            wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
-            if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
-                if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
-                    goto done;
-                }
-                wchar_t *sep = wcsrchr(origin_dirname, SEP);
-                if (sep) {
-                    *sep = L'\0';
-                    if (wcscmp(cwd, origin_dirname) == 0) {
-                        is_script_shadowing_stdlib = 1;
+        if (stdlib && PyAnySet_Check(stdlib)) {
+            int rc = PySet_Contains(stdlib, mod_name);
+            if (rc == 1) {
+                wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
+                if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
+                    if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
+                        goto done;
+                    }
+                    wchar_t *sep = wcsrchr(origin_dirname, SEP);
+                    if (sep) {
+                        *sep = L'\0';
+                        if (wcscmp(cwd, origin_dirname) == 0) {
+                            is_script_shadowing_stdlib = 1;
+                        }
                     }
                 }
             }
+            else if (rc == -1) {
+                goto done;
+            }
         }
     }
 

From 24ccd8aa536f7262e34fbf0cd64c92060446aec0 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 22 Jan 2024 14:54:45 -0800
Subject: [PATCH 12/48] add substr test

---
 Lib/test/test_import/__init__.py | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 49392ea6cbeffe..28b7ea01a060c5 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -824,6 +824,15 @@ def test_shadowing_stdlib_sys_edge_cases(self):
 import types
 collections.__spec__ = types.SimpleNamespace()
 collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+
+class substr(str):
+    __hash__ = None
+collections.__name__ = substr('collections')
+try:
+    collections.does_not_exist
+except TypeError as e:
+    print(str(e))
+
 import sys
 sys.stdlib_module_names = None
 try:
@@ -840,6 +849,7 @@ def test_shadowing_stdlib_sys_edge_cases(self):
         popen = script_helper.spawn_python('-c', program)
         stdout, stderr = popen.communicate()
         self.assertEqual(stdout.splitlines(), [
+            b"unhashable type: 'substr'",
             b"module 'collections' has no attribute 'does_not_exist'",
             b"module 'collections' has no attribute 'does_not_exist'",
         ])

From 47d7f6c23b4c3083e9122b6abdc7c3195cbf9325 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sun, 28 Jan 2024 02:38:17 -0800
Subject: [PATCH 13/48] remove dedent, fix whitespace, use bool

---
 Lib/test/test_import/__init__.py | 4 ++--
 Objects/moduleobject.c           | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 28b7ea01a060c5..773bb037eb597c 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -818,7 +818,7 @@ def test_cwd_script_shadowing_stdlib(self):
                 collections.does_not_exist
 
     def test_shadowing_stdlib_sys_edge_cases(self):
-        program = textwrap.dedent('''
+        program = '''
 import collections
 import os
 import types
@@ -845,7 +845,7 @@ class substr(str):
     collections.does_not_exist
 except AttributeError as e:
     print(str(e))
-''')
+'''
         popen = script_helper.spawn_python('-c', program)
         stdout, stderr = popen.communicate()
         self.assertEqual(stdout.splitlines(), [
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 2f32f30232cb6a..45e0639799cd68 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -853,7 +853,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         }
     }
 
-    int is_script_shadowing_stdlib = 0;
+    bool is_script_shadowing_stdlib = 0;
     // Check mod.__name__ in sys.stdlib_module_names
     // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
     if (origin) {
@@ -862,7 +862,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
             int rc = PySet_Contains(stdlib, mod_name);
             if (rc == 1) {
                 wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
-                if(_Py_wgetcwd(cwd, MAXPATHLEN)) {
+                if (_Py_wgetcwd(cwd, MAXPATHLEN)) {
                     if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
                         goto done;
                     }

From 5c0991db16eea14f8066d7730e9a5f818523733c Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sun, 28 Jan 2024 23:28:24 -0800
Subject: [PATCH 14/48] Rework to handle third party shadowing

---
 Objects/moduleobject.c | 106 ++++++++++++++++++++++++++++++-----------
 1 file changed, 79 insertions(+), 27 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 45e0639799cd68..17f6cf42e00284 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -786,6 +786,60 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
     return rc;
 }
 
+int
+_is_module_possibly_shadowing(PyObject *origin)
+{
+    // origin must be a unicode subtype
+    // Returns 1 if the module at origin could be shadowing a module of the
+    // same name. The exact condition we check is:
+    // not sys.flags.safe_path and os.path.dirname(origin) == sys.path[0]
+    // Returns 0 otherwise (or if we aren't sure)
+    // Returns -1 if an error occurred that should be propagated
+    if (origin == NULL) {
+        return 0;
+    }
+    const PyConfig *config = _Py_GetConfig();
+    if (config->safe_path) {
+        return 0;
+    }
+
+    PyObject *sys_path = PySys_GetObject(&_Py_ID(path));
+    if (sys_path == NULL || !PyList_Check(sys_path) || PyList_GET_SIZE(sys_path) == 0) {
+        return 0;
+    }
+    wchar_t sys_path_0[MAXPATHLEN];
+    int rc = PyUnicode_AsWideChar(PyList_GET_ITEM(sys_path, 0), sys_path_0, MAXPATHLEN - 1);
+    if (rc < 0) {
+        return -1;
+    }
+    assert(rc < MAXPATHLEN);
+    sys_path_0[rc] = L'\0';
+    if (rc == 0) {
+        // if sys.path[0] == "", treat it as if it were the current directory
+        if (!_Py_wgetcwd(sys_path_0, MAXPATHLEN)) {
+            return -1;
+        }
+    }
+
+    wchar_t origin_dirname[MAXPATHLEN];
+    rc = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN - 1);
+    if (rc < 0) {
+        return -1;
+    }
+    assert(rc < MAXPATHLEN);
+    origin_dirname[rc] = L'\0';
+
+    wchar_t *sep = wcsrchr(origin_dirname, SEP);
+    if (!sep) {
+        return 0;
+    }
+    *sep = L'\0';
+    if (wcscmp(sys_path_0, origin_dirname) == 0) {
+        return 1;
+    }
+    return 0;
+}
+
 PyObject*
 _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
 {
@@ -853,44 +907,42 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         }
     }
 
-    bool is_script_shadowing_stdlib = 0;
-    // Check mod.__name__ in sys.stdlib_module_names
-    // and os.path.dirname(mod.__spec__.origin) == os.getcwd()
-    if (origin) {
-        PyObject *stdlib = PySys_GetObject("stdlib_module_names");
-        if (stdlib && PyAnySet_Check(stdlib)) {
-            int rc = PySet_Contains(stdlib, mod_name);
-            if (rc == 1) {
-                wchar_t cwd[MAXPATHLEN], origin_dirname[MAXPATHLEN];
-                if (_Py_wgetcwd(cwd, MAXPATHLEN)) {
-                    if (PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN) < 0) {
-                        goto done;
-                    }
-                    wchar_t *sep = wcsrchr(origin_dirname, SEP);
-                    if (sep) {
-                        *sep = L'\0';
-                        if (wcscmp(cwd, origin_dirname) == 0) {
-                            is_script_shadowing_stdlib = 1;
-                        }
-                    }
-                }
-            }
-            else if (rc == -1) {
+    int is_possibly_shadowing = _is_module_possibly_shadowing(origin);
+    if (is_possibly_shadowing < 0) {
+        goto done;
+    }
+    int is_possibly_shadowing_stdlib = 0;
+    if (is_possibly_shadowing == 1) {
+        PyObject *stdlib_modules = PySys_GetObject("stdlib_module_names");
+        if (stdlib_modules && PyAnySet_Check(stdlib_modules)) {
+            is_possibly_shadowing_stdlib = PySet_Contains(stdlib_modules, mod_name);
+            if (is_possibly_shadowing_stdlib == -1) {
                 goto done;
             }
         }
     }
 
-    if (is_script_shadowing_stdlib == 1) {
+    if (is_possibly_shadowing_stdlib) {
+        assert(origin);
         PyErr_Format(PyExc_AttributeError,
                     "module '%U' has no attribute '%U' "
-                    "(most likely due to '%U' shadowing the standard library "
-                    "module named '%U')",
+                    "(consider renaming '%U' since it has the same "
+                    "name as the standard library module named '%U')",
                     mod_name, name, origin, mod_name);
     } else {
         int rc = _PyModuleSpec_IsInitializing(spec);
         if (rc > 0) {
-            if (origin) {
+            if (is_possibly_shadowing) {
+                assert(origin);
+                // For third party modules, only mention the possibility of
+                // shadowing if the module is being initialized.
+                PyErr_Format(PyExc_AttributeError,
+                            "module '%U' has no attribute '%U' "
+                            "(consider renaming '%U' if it has the same name "
+                            "as a third party module you intended to import)",
+                            mod_name, name, origin);
+            }
+            else if (origin) {
                 PyErr_Format(PyExc_AttributeError,
                             "partially initialized "
                             "module '%U' from '%U' has no attribute '%U' "

From dec51f3e1f1f8d4b9f074c8cc62220e6e3f8225f Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:10:01 -0800
Subject: [PATCH 15/48] Update test cases

---
 Lib/test/test_import/__init__.py | 127 ++++++++++++++++++++++---------
 1 file changed, 89 insertions(+), 38 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 773bb037eb597c..d02eea73154f12 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -790,41 +790,79 @@ def test_issue105979(self):
         self.assertIn("Frozen object named 'x' is invalid",
                       str(cm.exception))
 
-    def test_cwd_script_shadowing_stdlib(self):
-        with CleanImport('collections'):
-            import collections
-            collections.__spec__ = types.SimpleNamespace()
-            collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
+    def test_script_shadowing_stdlib(self):
+        with os_helper.temp_dir() as tmp:
+            with open(os.path.join(tmp, "collections.py"), "w", encoding='utf-8') as f:
+                f.write("import collections\ncollections.defaultdict")
 
-            with self.assertRaisesRegex(
-                AttributeError,
-                r"module 'collections' has no attribute 'does_not_exist' \(most "
-                r"likely due to '.*collections.py' shadowing the standard "
-                r"library module named 'collections'\)"
-            ):
-                collections.does_not_exist
+            expected_error = (
+                rb"AttributeError: module 'collections' has no attribute 'defaultdict' "
+                rb"\(consider renaming '.*collections.py' since it has the "
+                rb"same name as the standard library module named 'collections'\)"
+            )
+
+            popen = script_helper.spawn_python('collections.py', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-m', 'collections', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-c', 'import collections', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            # and there's no error at all when using -P
+            popen = script_helper.spawn_python('-P', 'collections.py', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(stdout, b'')
+
+    def test_script_shadowing_third_party(self):
+        with os_helper.temp_dir() as tmp:
+            with open(os.path.join(tmp, "numpy.py"), "w", encoding='utf-8') as f:
+                f.write("import numpy\nnumpy.array")
+
+            expected_error = (
+                rb"AttributeError: module 'numpy' has no attribute 'array' "
+                rb"\(consider renaming '.*numpy.py' if it has the "
+                rb"same name as a third party module you intended to import\)\n\Z"
+            )
+
+            popen = script_helper.spawn_python('numpy.py', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-m', 'numpy', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-c', 'import numpy', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+    def test_script_possibly_shadowing(self):
+        with os_helper.temp_dir() as tmp:
+            with open(os.path.join(tmp, "numpy.py"), "w", encoding='utf-8') as f:
+                f.write("this_script_does_not_attempt_to_import_numpy = True")
+
+            expected_error = (
+                rb"AttributeError: module 'numpy' has no attribute 'attr'\n\Z"
+            )
+
+            popen = script_helper.spawn_python('-c', 'import numpy; numpy.attr', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
 
-            del collections.__spec__.origin
-            with self.assertRaisesRegex(
-                AttributeError,
-                r"module 'collections' has no attribute 'does_not_exist'$"
-            ):
-                collections.does_not_exist
-            del collections.__spec__
-            with self.assertRaisesRegex(
-                AttributeError,
-                r"module 'collections' has no attribute 'does_not_exist'$"
-            ):
-                collections.does_not_exist
 
     def test_shadowing_stdlib_sys_edge_cases(self):
-        program = '''
+        with os_helper.temp_dir() as tmp:
+            with open(os.path.join(tmp, "collections.py"), "w", encoding='utf-8') as f:
+                f.write("shadowing_module = True")
+            with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                f.write("""
 import collections
-import os
-import types
-collections.__spec__ = types.SimpleNamespace()
-collections.__spec__.origin = os.path.join(os.getcwd(), 'collections.py')
-
+collections.shadowing_module
 class substr(str):
     __hash__ = None
 collections.__name__ = substr('collections')
@@ -832,6 +870,16 @@ class substr(str):
     collections.does_not_exist
 except TypeError as e:
     print(str(e))
+""")
+
+            popen = script_helper.spawn_python("main.py", cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(stdout, b"unhashable type: 'substr'\n")
+
+            with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                f.write("""
+import collections
+collections.shadowing_module
 
 import sys
 sys.stdlib_module_names = None
@@ -845,14 +893,17 @@ class substr(str):
     collections.does_not_exist
 except AttributeError as e:
     print(str(e))
-'''
-        popen = script_helper.spawn_python('-c', program)
-        stdout, stderr = popen.communicate()
-        self.assertEqual(stdout.splitlines(), [
-            b"unhashable type: 'substr'",
-            b"module 'collections' has no attribute 'does_not_exist'",
-            b"module 'collections' has no attribute 'does_not_exist'",
-        ])
+""")
+
+            popen = script_helper.spawn_python("main.py", cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(
+                stdout.splitlines(),
+                [
+                    b"module 'collections' has no attribute 'does_not_exist'",
+                    b"module 'collections' has no attribute 'does_not_exist'",
+                ],
+            )
 
 
 @skip_if_dont_write_bytecode

From a32411b6c2955f3ce1c83c73a4dbeab549470d65 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:12:31 -0800
Subject: [PATCH 16/48] Update What's New

---
 Doc/whatsnew/3.13.rst | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index b9b4b0bcfd8e1a..8e299c465aee17 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -95,9 +95,8 @@ Improved Error Messages
   (Contributed by Pablo Galindo Salgado in :gh:`112730`.)
 
 * A common mistake is to write a script with the same name as a
-  standard library module. The interpreter now detects this and
-  displays a more helpful error message.
-  (Contributed by Shantanu Jain in :gh:`95754`.)
+  standard library module. When this results in errors, we now
+  display a more helpful error message:
 
   .. code-block:: shell-session
 
@@ -109,7 +108,25 @@ Improved Error Messages
       File "/home/random.py", line 1, in <module>
         import random; print(random.randint(5))
                             ^^^^^^^^^^^^^^
-    AttributeError: module 'random' has no attribute 'randint' (most likely due to '/home/random.py' shadowing the standard library module named 'random')
+    AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random')
+
+  Similarly, if a script has the same name as a third party
+  module it attempts to import, we also display a more helpful
+  error message:
+
+  .. code-block:: shell-session
+
+    $ python numpy.py
+    Traceback (most recent call last):
+      File "/home/numpy.py", line 1, in <module>
+        import numpy as np; np.array([1,2,3])
+        ^^^^^^^^^^^^^^^^^^
+      File "/home/numpy.py", line 1, in <module>
+        import numpy as np; np.array([1,2,3])
+                            ^^^^^^^^
+    AttributeError: module 'numpy' has no attribute 'array' (consider renaming '/home/numpy.py' if it has the same name as a third party module you intended to import)
+
+  (Contributed by Shantanu Jain in :gh:`95754`.)
 
 
 Other Language Changes

From c1b79fa301a442bf71a8b2194a4615024bdf3348 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:21:06 -0800
Subject: [PATCH 17/48] Tweak test

---
 Lib/test/test_import/__init__.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index d02eea73154f12..5b6034ace3b233 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -801,7 +801,7 @@ def test_script_shadowing_stdlib(self):
                 rb"same name as the standard library module named 'collections'\)"
             )
 
-            popen = script_helper.spawn_python('collections.py', cwd=tmp)
+            popen = script_helper.spawn_python(os.path.join(tmp, "collections.py"))
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
@@ -829,7 +829,7 @@ def test_script_shadowing_third_party(self):
                 rb"same name as a third party module you intended to import\)\n\Z"
             )
 
-            popen = script_helper.spawn_python('numpy.py', cwd=tmp)
+            popen = script_helper.spawn_python(os.path.join(tmp, "numpy.py"))
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 

From 1feabb04b738fc778c40aa1999bf4208cf3545f9 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:39:37 -0800
Subject: [PATCH 18/48] Update news entry

---
 .../2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst            | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst b/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst
index 30800cb94418c1..588be2d28cd76e 100644
--- a/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst	
+++ b/Misc/NEWS.d/next/Core and Builtins/2024-01-07-03-38-34.gh-issue-95754.aPjEBG.rst	
@@ -1 +1,4 @@
-Improve the error message when a script in the current directory shadows a module from the standard library.
+Improve the error message when a script shadowing a module from the standard
+library causes :exc:`AttributeError` to be raised. Similarly, improve the error
+message when a script shadowing a third party module attempts to access an
+attribute from that third party module while still initialising.

From eaf08ac3048cec59ad4336c2df9dfe7c863722d4 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:47:02 -0800
Subject: [PATCH 19/48] Tweak test names

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

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 5b6034ace3b233..619beb996448c4 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -841,7 +841,7 @@ def test_script_shadowing_third_party(self):
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
-    def test_script_possibly_shadowing(self):
+    def test_script_maybe_not_shadowing_third_party(self):
         with os_helper.temp_dir() as tmp:
             with open(os.path.join(tmp, "numpy.py"), "w", encoding='utf-8') as f:
                 f.write("this_script_does_not_attempt_to_import_numpy = True")
@@ -854,8 +854,7 @@ def test_script_possibly_shadowing(self):
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
-
-    def test_shadowing_stdlib_sys_edge_cases(self):
+    def test_script_shadowing_stdlib_edge_cases(self):
         with os_helper.temp_dir() as tmp:
             with open(os.path.join(tmp, "collections.py"), "w", encoding='utf-8') as f:
                 f.write("shadowing_module = True")

From d9eb4244569e145185fc5425c52da68299770c6f Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:51:09 -0800
Subject: [PATCH 20/48] Tweak What's New language

---
 Doc/whatsnew/3.13.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 8e299c465aee17..ee22a6bb277801 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -111,8 +111,8 @@ Improved Error Messages
     AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random')
 
   Similarly, if a script has the same name as a third party
-  module it attempts to import, we also display a more helpful
-  error message:
+  module it attempts to import, and this results in errors,
+  we also display a more helpful error message:
 
   .. code-block:: shell-session
 

From 69df558c991e155e9ae5e1ed449423558489f7f2 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 00:57:20 -0800
Subject: [PATCH 21/48] Tweak docstring, fix accidental commit

---
 Objects/moduleobject.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 17f6cf42e00284..4117e6b941dcb6 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -791,8 +791,8 @@ _is_module_possibly_shadowing(PyObject *origin)
 {
     // origin must be a unicode subtype
     // Returns 1 if the module at origin could be shadowing a module of the
-    // same name. The exact condition we check is:
-    // not sys.flags.safe_path and os.path.dirname(origin) == sys.path[0]
+    // same name later in the module search path. The condition we check is basically:
+    // not sys.flags.safe_path and os.path.dirname(origin) == (sys.path[0] or os.getcwd())
     // Returns 0 otherwise (or if we aren't sure)
     // Returns -1 if an error occurred that should be propagated
     if (origin == NULL) {
@@ -803,7 +803,7 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
 
-    PyObject *sys_path = PySys_GetObject(&_Py_ID(path));
+    PyObject *sys_path = PySys_GetObject("path");
     if (sys_path == NULL || !PyList_Check(sys_path) || PyList_GET_SIZE(sys_path) == 0) {
         return 0;
     }

From ef30d332b37f9c69779e8374c7f4f1b244b40bee Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 01:02:02 -0800
Subject: [PATCH 22/48] Add hyphen in third-party

---
 Doc/whatsnew/3.13.rst            | 4 ++--
 Lib/test/test_import/__init__.py | 2 +-
 Objects/moduleobject.c           | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index ee22a6bb277801..eaf658348f565c 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -110,7 +110,7 @@ Improved Error Messages
                             ^^^^^^^^^^^^^^
     AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random')
 
-  Similarly, if a script has the same name as a third party
+  Similarly, if a script has the same name as a third-party
   module it attempts to import, and this results in errors,
   we also display a more helpful error message:
 
@@ -124,7 +124,7 @@ Improved Error Messages
       File "/home/numpy.py", line 1, in <module>
         import numpy as np; np.array([1,2,3])
                             ^^^^^^^^
-    AttributeError: module 'numpy' has no attribute 'array' (consider renaming '/home/numpy.py' if it has the same name as a third party module you intended to import)
+    AttributeError: module 'numpy' has no attribute 'array' (consider renaming '/home/numpy.py' if it has the same name as a third-party module you intended to import)
 
   (Contributed by Shantanu Jain in :gh:`95754`.)
 
diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 619beb996448c4..b1b2a8a3c7d9be 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -826,7 +826,7 @@ def test_script_shadowing_third_party(self):
             expected_error = (
                 rb"AttributeError: module 'numpy' has no attribute 'array' "
                 rb"\(consider renaming '.*numpy.py' if it has the "
-                rb"same name as a third party module you intended to import\)\n\Z"
+                rb"same name as a third-party module you intended to import\)\n\Z"
             )
 
             popen = script_helper.spawn_python(os.path.join(tmp, "numpy.py"))
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 4117e6b941dcb6..dad5bb449ab376 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -934,12 +934,12 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         if (rc > 0) {
             if (is_possibly_shadowing) {
                 assert(origin);
-                // For third party modules, only mention the possibility of
+                // For third-party modules, only mention the possibility of
                 // shadowing if the module is being initialized.
                 PyErr_Format(PyExc_AttributeError,
                             "module '%U' has no attribute '%U' "
                             "(consider renaming '%U' if it has the same name "
-                            "as a third party module you intended to import)",
+                            "as a third-party module you intended to import)",
                             mod_name, name, origin);
             }
             else if (origin) {

From f1c9ee9a12c40346d499caac9e4e1f94851c3c5f Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 01:10:35 -0800
Subject: [PATCH 23/48] Tweak test attribute

---
 Lib/test/test_import/__init__.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index b1b2a8a3c7d9be..ad8d223a4f46a6 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -866,7 +866,7 @@ class substr(str):
     __hash__ = None
 collections.__name__ = substr('collections')
 try:
-    collections.does_not_exist
+    collections.defaultdict
 except TypeError as e:
     print(str(e))
 """)
@@ -883,13 +883,13 @@ class substr(str):
 import sys
 sys.stdlib_module_names = None
 try:
-    collections.does_not_exist
+    collections.defaultdict
 except AttributeError as e:
     print(str(e))
 
 del sys.stdlib_module_names
 try:
-    collections.does_not_exist
+    collections.defaultdict
 except AttributeError as e:
     print(str(e))
 """)
@@ -899,8 +899,8 @@ class substr(str):
             self.assertEqual(
                 stdout.splitlines(),
                 [
-                    b"module 'collections' has no attribute 'does_not_exist'",
-                    b"module 'collections' has no attribute 'does_not_exist'",
+                    b"module 'collections' has no attribute 'defaultdict'",
+                    b"module 'collections' has no attribute 'defaultdict'",
                 ],
             )
 

From a588c15177ad7c3ababc9f2b74abdc8d3cbbd853 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 01:15:57 -0800
Subject: [PATCH 24/48] Fix nit

---
 Objects/moduleobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index dad5bb449ab376..60f9d47053b77e 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -908,7 +908,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     }
 
     int is_possibly_shadowing = _is_module_possibly_shadowing(origin);
-    if (is_possibly_shadowing < 0) {
+    if (is_possibly_shadowing == -1) {
         goto done;
     }
     int is_possibly_shadowing_stdlib = 0;

From ea0d2ad3743165a140a4fc0f7a6ca829ce3f15a4 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 01:21:55 -0800
Subject: [PATCH 25/48] Add missing static

---
 Objects/moduleobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 60f9d47053b77e..fe8508af50a7aa 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -786,7 +786,7 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
     return rc;
 }
 
-int
+static int
 _is_module_possibly_shadowing(PyObject *origin)
 {
     // origin must be a unicode subtype

From 61b55175e2decbefb69c1c37f055e6f2a4455964 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 01:39:20 -0800
Subject: [PATCH 26/48] Fix test failures on Windows

---
 Lib/test/test_import/__init__.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index ad8d223a4f46a6..b47c2d0f751c5b 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -826,7 +826,7 @@ def test_script_shadowing_third_party(self):
             expected_error = (
                 rb"AttributeError: module 'numpy' has no attribute 'array' "
                 rb"\(consider renaming '.*numpy.py' if it has the "
-                rb"same name as a third-party module you intended to import\)\n\Z"
+                rb"same name as a third-party module you intended to import\)\s+\Z"
             )
 
             popen = script_helper.spawn_python(os.path.join(tmp, "numpy.py"))
@@ -847,7 +847,7 @@ def test_script_maybe_not_shadowing_third_party(self):
                 f.write("this_script_does_not_attempt_to_import_numpy = True")
 
             expected_error = (
-                rb"AttributeError: module 'numpy' has no attribute 'attr'\n\Z"
+                rb"AttributeError: module 'numpy' has no attribute 'attr'\s+\Z"
             )
 
             popen = script_helper.spawn_python('-c', 'import numpy; numpy.attr', cwd=tmp)
@@ -873,7 +873,7 @@ class substr(str):
 
             popen = script_helper.spawn_python("main.py", cwd=tmp)
             stdout, stderr = popen.communicate()
-            self.assertEqual(stdout, b"unhashable type: 'substr'\n")
+            self.assertEqual(stdout.rstrip(), b"unhashable type: 'substr'")
 
             with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
                 f.write("""

From a6b3d83012437c0dba2bea36fda878152d9dfd38 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 02:18:18 -0800
Subject: [PATCH 27/48] Use Py_ssize_t

---
 Objects/moduleobject.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index fe8508af50a7aa..2a138a5a072843 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -808,13 +808,13 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
     wchar_t sys_path_0[MAXPATHLEN];
-    int rc = PyUnicode_AsWideChar(PyList_GET_ITEM(sys_path, 0), sys_path_0, MAXPATHLEN - 1);
-    if (rc < 0) {
+    Py_ssize_t size = PyUnicode_AsWideChar(PyList_GET_ITEM(sys_path, 0), sys_path_0, MAXPATHLEN - 1);
+    if (size < 0) {
         return -1;
     }
-    assert(rc < MAXPATHLEN);
-    sys_path_0[rc] = L'\0';
-    if (rc == 0) {
+    assert(size < MAXPATHLEN);
+    sys_path_0[size] = L'\0';
+    if (size == 0) {
         // if sys.path[0] == "", treat it as if it were the current directory
         if (!_Py_wgetcwd(sys_path_0, MAXPATHLEN)) {
             return -1;
@@ -822,12 +822,12 @@ _is_module_possibly_shadowing(PyObject *origin)
     }
 
     wchar_t origin_dirname[MAXPATHLEN];
-    rc = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN - 1);
-    if (rc < 0) {
+    size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN - 1);
+    if (size < 0) {
         return -1;
     }
-    assert(rc < MAXPATHLEN);
-    origin_dirname[rc] = L'\0';
+    assert(size < MAXPATHLEN);
+    origin_dirname[size] = L'\0';
 
     wchar_t *sep = wcsrchr(origin_dirname, SEP);
     if (!sep) {

From fe2506835fcb5c11a4e6db51fcab932a4076ce19 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 02:24:53 -0800
Subject: [PATCH 28/48] Add test case for bad sys.path

---
 Lib/test/test_import/__init__.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index b47c2d0f751c5b..6d05a4c5ad6ac4 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -892,6 +892,12 @@ class substr(str):
     collections.defaultdict
 except AttributeError as e:
     print(str(e))
+
+sys.path = [0]
+try:
+    collections.defaultdict
+except TypeError as e:
+    print(str(e))
 """)
 
             popen = script_helper.spawn_python("main.py", cwd=tmp)
@@ -901,6 +907,7 @@ class substr(str):
                 [
                     b"module 'collections' has no attribute 'defaultdict'",
                     b"module 'collections' has no attribute 'defaultdict'",
+                    b"bad argument type for built-in operation",
                 ],
             )
 

From 09813021ce5b336174c0a762220ba501705608a8 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 02:29:52 -0800
Subject: [PATCH 29/48] Further tweaks

---
 Lib/test/test_import/__init__.py |  4 ++--
 Objects/moduleobject.c           | 12 ++++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 6d05a4c5ad6ac4..22621b66bbcac6 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -896,7 +896,7 @@ class substr(str):
 sys.path = [0]
 try:
     collections.defaultdict
-except TypeError as e:
+except AttributeError as e:
     print(str(e))
 """)
 
@@ -907,7 +907,7 @@ class substr(str):
                 [
                     b"module 'collections' has no attribute 'defaultdict'",
                     b"module 'collections' has no attribute 'defaultdict'",
-                    b"bad argument type for built-in operation",
+                    b"module 'collections' has no attribute 'defaultdict'",
                 ],
             )
 
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 2a138a5a072843..8b0010f52e1c30 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -807,8 +807,12 @@ _is_module_possibly_shadowing(PyObject *origin)
     if (sys_path == NULL || !PyList_Check(sys_path) || PyList_GET_SIZE(sys_path) == 0) {
         return 0;
     }
-    wchar_t sys_path_0[MAXPATHLEN];
-    Py_ssize_t size = PyUnicode_AsWideChar(PyList_GET_ITEM(sys_path, 0), sys_path_0, MAXPATHLEN - 1);
+    PyObject *py_sys_path_0 = PyList_GET_ITEM(sys_path, 0);
+    if (!PyUnicode_Check(py_sys_path_0)) {
+        return 0;
+    }
+    wchar_t sys_path_0[MAXPATHLEN + 1];
+    Py_ssize_t size = PyUnicode_AsWideChar(py_sys_path_0, sys_path_0, MAXPATHLEN);
     if (size < 0) {
         return -1;
     }
@@ -821,8 +825,8 @@ _is_module_possibly_shadowing(PyObject *origin)
         }
     }
 
-    wchar_t origin_dirname[MAXPATHLEN];
-    size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN - 1);
+    wchar_t origin_dirname[MAXPATHLEN + 1];
+    size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
     if (size < 0) {
         return -1;
     }

From 5069b988f6f67dd454802119f8bd4580a7bda2ba Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 29 Jan 2024 11:23:59 -0800
Subject: [PATCH 30/48] Tweak assert for +1 logic

---
 Objects/moduleobject.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 8b0010f52e1c30..7fb0febcd8fb4c 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -816,7 +816,7 @@ _is_module_possibly_shadowing(PyObject *origin)
     if (size < 0) {
         return -1;
     }
-    assert(size < MAXPATHLEN);
+    assert(size <= MAXPATHLEN);
     sys_path_0[size] = L'\0';
     if (size == 0) {
         // if sys.path[0] == "", treat it as if it were the current directory
@@ -830,7 +830,7 @@ _is_module_possibly_shadowing(PyObject *origin)
     if (size < 0) {
         return -1;
     }
-    assert(size < MAXPATHLEN);
+    assert(size <= MAXPATHLEN);
     origin_dirname[size] = L'\0';
 
     wchar_t *sep = wcsrchr(origin_dirname, SEP);

From 9977cea2066be41bdfd758392c0390518a7a907b Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 2 Feb 2024 01:00:33 -0800
Subject: [PATCH 31/48] Use config->sys_path_0 / config->module_search_path +
 add test for sys.path editing + avoid collections warning from traceback.py

---
 Lib/test/test_import/__init__.py | 67 +++++++++++++++++++++-----------
 Objects/moduleobject.c           | 56 +++++++++++++-------------
 2 files changed, 75 insertions(+), 48 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 22621b66bbcac6..4129a0bf1c09e6 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -792,29 +792,29 @@ def test_issue105979(self):
 
     def test_script_shadowing_stdlib(self):
         with os_helper.temp_dir() as tmp:
-            with open(os.path.join(tmp, "collections.py"), "w", encoding='utf-8') as f:
-                f.write("import collections\ncollections.defaultdict")
+            with open(os.path.join(tmp, "fractions.py"), "w", encoding='utf-8') as f:
+                f.write("import fractions\nfractions.Fraction")
 
             expected_error = (
-                rb"AttributeError: module 'collections' has no attribute 'defaultdict' "
-                rb"\(consider renaming '.*collections.py' since it has the "
-                rb"same name as the standard library module named 'collections'\)"
+                rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
+                rb"\(consider renaming '.*fractions.py' since it has the "
+                rb"same name as the standard library module named 'fractions'\)"
             )
 
-            popen = script_helper.spawn_python(os.path.join(tmp, "collections.py"))
+            popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"))
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
-            popen = script_helper.spawn_python('-m', 'collections', cwd=tmp)
+            popen = script_helper.spawn_python('-m', 'fractions', cwd=tmp)
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
-            popen = script_helper.spawn_python('-c', 'import collections', cwd=tmp)
+            popen = script_helper.spawn_python('-c', 'import fractions', cwd=tmp)
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
             # and there's no error at all when using -P
-            popen = script_helper.spawn_python('-P', 'collections.py', cwd=tmp)
+            popen = script_helper.spawn_python('-P', 'fractions.py', cwd=tmp)
             stdout, stderr = popen.communicate()
             self.assertEqual(stdout, b'')
 
@@ -856,17 +856,17 @@ def test_script_maybe_not_shadowing_third_party(self):
 
     def test_script_shadowing_stdlib_edge_cases(self):
         with os_helper.temp_dir() as tmp:
-            with open(os.path.join(tmp, "collections.py"), "w", encoding='utf-8') as f:
+            with open(os.path.join(tmp, "fractions.py"), "w", encoding='utf-8') as f:
                 f.write("shadowing_module = True")
             with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
                 f.write("""
-import collections
-collections.shadowing_module
+import fractions
+fractions.shadowing_module
 class substr(str):
     __hash__ = None
-collections.__name__ = substr('collections')
+fractions.__name__ = substr('fractions')
 try:
-    collections.defaultdict
+    fractions.Fraction
 except TypeError as e:
     print(str(e))
 """)
@@ -877,25 +877,25 @@ class substr(str):
 
             with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
                 f.write("""
-import collections
-collections.shadowing_module
+import fractions
+fractions.shadowing_module
 
 import sys
 sys.stdlib_module_names = None
 try:
-    collections.defaultdict
+    fractions.Fraction
 except AttributeError as e:
     print(str(e))
 
 del sys.stdlib_module_names
 try:
-    collections.defaultdict
+    fractions.Fraction
 except AttributeError as e:
     print(str(e))
 
 sys.path = [0]
 try:
-    collections.defaultdict
+    fractions.Fraction
 except AttributeError as e:
     print(str(e))
 """)
@@ -905,12 +905,35 @@ class substr(str):
             self.assertEqual(
                 stdout.splitlines(),
                 [
-                    b"module 'collections' has no attribute 'defaultdict'",
-                    b"module 'collections' has no attribute 'defaultdict'",
-                    b"module 'collections' has no attribute 'defaultdict'",
+                    b"module 'fractions' has no attribute 'Fraction'",
+                    b"module 'fractions' has no attribute 'Fraction'",
+                    b"module 'fractions' has no attribute 'Fraction'",
                 ],
             )
 
+    def test_script_shadowing_stdlib_sys_path_modification(self):
+        with os_helper.temp_dir() as tmp:
+            with open(os.path.join(tmp, "fractions.py"), "w", encoding='utf-8') as f:
+                f.write("shadowing_module = True")
+
+            expected_error = (
+                rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
+                rb"\(consider renaming '.*fractions.py' since it has the "
+                rb"same name as the standard library module named 'fractions'\)"
+            )
+
+            with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                f.write("""
+import sys
+sys.path.insert(0, "this_folder_does_not_exist")
+import fractions
+fractions.Fraction
+""")
+
+            popen = script_helper.spawn_python("main.py", cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
 
 @skip_if_dont_write_bytecode
 class FilePermissionTests(unittest.TestCase):
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 7fb0febcd8fb4c..e5b35efa8b5552 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -803,30 +803,9 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
 
-    PyObject *sys_path = PySys_GetObject("path");
-    if (sys_path == NULL || !PyList_Check(sys_path) || PyList_GET_SIZE(sys_path) == 0) {
-        return 0;
-    }
-    PyObject *py_sys_path_0 = PyList_GET_ITEM(sys_path, 0);
-    if (!PyUnicode_Check(py_sys_path_0)) {
-        return 0;
-    }
-    wchar_t sys_path_0[MAXPATHLEN + 1];
-    Py_ssize_t size = PyUnicode_AsWideChar(py_sys_path_0, sys_path_0, MAXPATHLEN);
-    if (size < 0) {
-        return -1;
-    }
-    assert(size <= MAXPATHLEN);
-    sys_path_0[size] = L'\0';
-    if (size == 0) {
-        // if sys.path[0] == "", treat it as if it were the current directory
-        if (!_Py_wgetcwd(sys_path_0, MAXPATHLEN)) {
-            return -1;
-        }
-    }
-
+    // os.path.dirname(origin)
     wchar_t origin_dirname[MAXPATHLEN + 1];
-    size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
+    Py_ssize_t size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
     if (size < 0) {
         return -1;
     }
@@ -838,10 +817,35 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
     *sep = L'\0';
-    if (wcscmp(sys_path_0, origin_dirname) == 0) {
-        return 1;
+
+    // sys.path[0] or os.getcwd()
+    wchar_t *sys_path_0 = config->sys_path_0;
+    if (!sys_path_0) {
+        if (!config->module_search_paths_set || config->module_search_paths.length == 0) {
+            return 0;
+        }
+        sys_path_0 = config->module_search_paths.items[0];
+        assert(sys_path_0 != NULL);
     }
-    return 0;
+    bool sys_path_allocated = false;
+    if (sys_path_0[0] == L'\0') {
+        // if sys.path[0] == "", treat it as if it were the current directory
+        sys_path_0 = PyMem_RawMalloc(MAXPATHLEN * sizeof(wchar_t));
+        if (!sys_path_0) {
+            return -1;
+        }
+        sys_path_allocated = true;
+        if (!_Py_wgetcwd(sys_path_0, MAXPATHLEN)) {
+            PyMem_RawFree(sys_path_0);
+            return -1;
+        }
+    }
+
+    int result = wcscmp(sys_path_0, origin_dirname) == 0;
+    if (sys_path_allocated) {
+        PyMem_RawFree(sys_path_0);
+    }
+    return result;
 }
 
 PyObject*

From f74226187ad3ba6f29d5513abd734d263367302c Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 3 Feb 2024 23:03:48 -0800
Subject: [PATCH 32/48] stack allocate

---
 Objects/moduleobject.c | 21 +++++----------------
 1 file changed, 5 insertions(+), 16 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index e5b35efa8b5552..a7332f9b5ce7b8 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -821,30 +821,19 @@ _is_module_possibly_shadowing(PyObject *origin)
     // sys.path[0] or os.getcwd()
     wchar_t *sys_path_0 = config->sys_path_0;
     if (!sys_path_0) {
-        if (!config->module_search_paths_set || config->module_search_paths.length == 0) {
-            return 0;
-        }
-        sys_path_0 = config->module_search_paths.items[0];
-        assert(sys_path_0 != NULL);
+        return 0;
     }
-    bool sys_path_allocated = false;
+
+    wchar_t sys_path_0_buf[MAXPATHLEN];
     if (sys_path_0[0] == L'\0') {
         // if sys.path[0] == "", treat it as if it were the current directory
-        sys_path_0 = PyMem_RawMalloc(MAXPATHLEN * sizeof(wchar_t));
-        if (!sys_path_0) {
-            return -1;
-        }
-        sys_path_allocated = true;
-        if (!_Py_wgetcwd(sys_path_0, MAXPATHLEN)) {
-            PyMem_RawFree(sys_path_0);
+        if (!_Py_wgetcwd(sys_path_0_buf, MAXPATHLEN)) {
             return -1;
         }
+        sys_path_0 = sys_path_0_buf;
     }
 
     int result = wcscmp(sys_path_0, origin_dirname) == 0;
-    if (sys_path_allocated) {
-        PyMem_RawFree(sys_path_0);
-    }
     return result;
 }
 

From 3d205f3e8f638181fc5219f88360288d9ce8f0e6 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Sat, 3 Feb 2024 23:08:31 -0800
Subject: [PATCH 33/48] more cwd tests

---
 Lib/test/test_import/__init__.py | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 4129a0bf1c09e6..997f91f7ee0927 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -801,7 +801,7 @@ def test_script_shadowing_stdlib(self):
                 rb"same name as the standard library module named 'fractions'\)"
             )
 
-            popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"))
+            popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"), cwd=tmp)
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
 
@@ -818,6 +818,22 @@ def test_script_shadowing_stdlib(self):
             stdout, stderr = popen.communicate()
             self.assertEqual(stdout, b'')
 
+            tmp_child = os.path.join(tmp, "child")
+            os.mkdir(tmp_child)
+
+            # test the logic in with different cwd
+            popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"), cwd=tmp_child)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-m', 'fractions', cwd=tmp_child)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(stdout, b'')  # no error
+
+            popen = script_helper.spawn_python('-c', 'import fractions', cwd=tmp_child)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(stdout, b'')  # no error
+
     def test_script_shadowing_third_party(self):
         with os_helper.temp_dir() as tmp:
             with open(os.path.join(tmp, "numpy.py"), "w", encoding='utf-8') as f:

From 146d39488f81d81940f44fc92cb4a97f766cf25e Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Wed, 6 Mar 2024 14:51:53 -0800
Subject: [PATCH 34/48] further tweak error message

---
 Doc/whatsnew/3.13.rst            | 2 +-
 Lib/test/test_import/__init__.py | 6 ++++--
 Objects/moduleobject.c           | 3 ++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index c59cef56fed248..d05d6e32ba7f9e 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -115,7 +115,7 @@ Improved Error Messages
       File "/home/random.py", line 1, in <module>
         import random; print(random.randint(5))
                             ^^^^^^^^^^^^^^
-    AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random')
+    AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random'and takes precedence over it on sys.path)
 
   Similarly, if a script has the same name as a third-party
   module it attempts to import, and this results in errors,
diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 997f91f7ee0927..ba574c87347893 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -798,7 +798,8 @@ def test_script_shadowing_stdlib(self):
             expected_error = (
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
-                rb"same name as the standard library module named 'fractions'\)"
+                rb"same name as the standard library module named 'fractions'"
+                rb"and takes precedence over it on sys.path\)"
             )
 
             popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"), cwd=tmp)
@@ -935,7 +936,8 @@ def test_script_shadowing_stdlib_sys_path_modification(self):
             expected_error = (
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
-                rb"same name as the standard library module named 'fractions'\)"
+                rb"same name as the standard library module named 'fractions'"
+                rb"and takes precedence over it on sys.path\)"
             )
 
             with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index a7332f9b5ce7b8..e949f657b827f3 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -924,7 +924,8 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         PyErr_Format(PyExc_AttributeError,
                     "module '%U' has no attribute '%U' "
                     "(consider renaming '%U' since it has the same "
-                    "name as the standard library module named '%U')",
+                    "name as the standard library module named '%U'"
+                    "and takes precedence over it on sys.path)",
                     mod_name, name, origin, mod_name);
     } else {
         int rc = _PyModuleSpec_IsInitializing(spec);

From a38bad541151cf1ea9fc3c056576d4ada3e91d69 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Thu, 7 Mar 2024 23:32:44 -0800
Subject: [PATCH 35/48] control flow feedback

---
 Objects/moduleobject.c | 30 ++++++++++++++++++------------
 1 file changed, 18 insertions(+), 12 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index e949f657b827f3..07b2ec54a27db3 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -873,6 +873,8 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         return result;
     }
 
+    // The attribute was not found.  We make a best effort attempt at a useful error message,
+    // but only if we're not suppressing AttributeError.
     if (suppress == 1) {
         return NULL;
     }
@@ -890,18 +892,22 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         Py_DECREF(mod_name);
         return NULL;
     }
+    if (spec == NULL) {
+        PyErr_Format(PyExc_AttributeError,
+                     "module '%U' has no attribute '%U'",
+                     mod_name, name);
+        Py_DECREF(mod_name);
+        return NULL;
+    }
+
     PyObject *origin = NULL;
-    if (spec) {
-        int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
-        if (rc == -1) {
-            Py_DECREF(spec);
-            Py_DECREF(mod_name);
-            return NULL;
-        }
-        if (rc == 1 && !PyUnicode_Check(origin)) {
-            Py_DECREF(origin);
-            origin = NULL;
-        }
+    int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
+    if (rc == -1) {
+        goto done;
+    }
+    if (rc == 1 && !PyUnicode_Check(origin)) {
+        Py_DECREF(origin);
+        origin = NULL;
     }
 
     int is_possibly_shadowing = _is_module_possibly_shadowing(origin);
@@ -973,7 +979,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
 
 done:
     Py_XDECREF(origin);
-    Py_XDECREF(spec);
+    Py_DECREF(spec);
     Py_DECREF(mod_name);
     return NULL;
 }

From 822d8eb37ae783b9b05bb0520791eb7a735ca030 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 00:11:00 -0800
Subject: [PATCH 36/48] handle has_location correctly

---
 .../pycore_global_objects_fini_generated.h    |  1 +
 Include/internal/pycore_global_strings.h      |  1 +
 .../internal/pycore_runtime_init_generated.h  |  1 +
 .../internal/pycore_unicodeobject_generated.h |  3 ++
 Objects/moduleobject.c                        | 33 +++++++++++++++----
 5 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h
index 932738c3049882..03e57ac84643e7 100644
--- a/Include/internal/pycore_global_objects_fini_generated.h
+++ b/Include/internal/pycore_global_objects_fini_generated.h
@@ -973,6 +973,7 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) {
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(groups));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(h));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(handle));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(has_location));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(hash_name));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(header));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(headers));
diff --git a/Include/internal/pycore_global_strings.h b/Include/internal/pycore_global_strings.h
index da62b4f0a951ff..2acaf02a0bcc8c 100644
--- a/Include/internal/pycore_global_strings.h
+++ b/Include/internal/pycore_global_strings.h
@@ -462,6 +462,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(groups)
         STRUCT_FOR_ID(h)
         STRUCT_FOR_ID(handle)
+        STRUCT_FOR_ID(has_location)
         STRUCT_FOR_ID(hash_name)
         STRUCT_FOR_ID(header)
         STRUCT_FOR_ID(headers)
diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h
index 68fbbcb4378e17..8fbeae7e67ec21 100644
--- a/Include/internal/pycore_runtime_init_generated.h
+++ b/Include/internal/pycore_runtime_init_generated.h
@@ -971,6 +971,7 @@ extern "C" {
     INIT_ID(groups), \
     INIT_ID(h), \
     INIT_ID(handle), \
+    INIT_ID(has_location), \
     INIT_ID(hash_name), \
     INIT_ID(header), \
     INIT_ID(headers), \
diff --git a/Include/internal/pycore_unicodeobject_generated.h b/Include/internal/pycore_unicodeobject_generated.h
index c8458b4e36ccc9..72da512e42a9e4 100644
--- a/Include/internal/pycore_unicodeobject_generated.h
+++ b/Include/internal/pycore_unicodeobject_generated.h
@@ -1227,6 +1227,9 @@ _PyUnicode_InitStaticStrings(PyInterpreterState *interp) {
     string = &_Py_ID(handle);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);
+    string = &_Py_ID(has_location);
+    assert(_PyUnicode_CheckConsistency(string, 1));
+    _PyUnicode_InternInPlace(interp, &string);
     string = &_Py_ID(hash_name);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 07b2ec54a27db3..90311a92667477 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -786,6 +786,32 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
     return rc;
 }
 
+static int
+_get_file_origin_from_spec(PyObject *spec, PyObject **origin)
+{
+    PyObject *has_location = NULL;
+    int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(has_location), &has_location);
+    if (rc <= 0) {
+        return rc;
+    }
+    rc = PyObject_IsTrue(has_location);
+    Py_DECREF(has_location);
+    if (rc <= 0) {
+        return rc;
+    }
+    // has_location is true, so origin is a location
+    rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), origin);
+    if (rc <= 0) {
+        return rc;
+    }
+    if (!PyUnicode_Check(*origin)) {
+        Py_DECREF(*origin);
+        *origin = NULL;
+        return 0;
+    }
+    return 1;
+}
+
 static int
 _is_module_possibly_shadowing(PyObject *origin)
 {
@@ -901,14 +927,9 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     }
 
     PyObject *origin = NULL;
-    int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
-    if (rc == -1) {
+    if (_get_file_origin_from_spec(spec, &origin) == -1) {
         goto done;
     }
-    if (rc == 1 && !PyUnicode_Check(origin)) {
-        Py_DECREF(origin);
-        origin = NULL;
-    }
 
     int is_possibly_shadowing = _is_module_possibly_shadowing(origin);
     if (is_possibly_shadowing == -1) {

From 3ec37d19b2b80aa093f1358254e895668981e2c2 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 00:22:06 -0800
Subject: [PATCH 37/48] remove explicit safe path check

---
 Objects/moduleobject.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 90311a92667477..d870af69ac15b5 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -825,9 +825,12 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
     const PyConfig *config = _Py_GetConfig();
-    if (config->safe_path) {
+    // sys.path[0] or os.getcwd()
+    wchar_t *sys_path_0 = config->sys_path_0;
+    if (sys_path_0 == NULL) {
         return 0;
     }
+    assert(!config->safe_path);
 
     // os.path.dirname(origin)
     wchar_t origin_dirname[MAXPATHLEN + 1];
@@ -844,12 +847,6 @@ _is_module_possibly_shadowing(PyObject *origin)
     }
     *sep = L'\0';
 
-    // sys.path[0] or os.getcwd()
-    wchar_t *sys_path_0 = config->sys_path_0;
-    if (!sys_path_0) {
-        return 0;
-    }
-
     wchar_t sys_path_0_buf[MAXPATHLEN];
     if (sys_path_0[0] == L'\0') {
         // if sys.path[0] == "", treat it as if it were the current directory

From 64bb4fd9756397b352fd66e3c13274bc31eb07cf Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 00:25:30 -0800
Subject: [PATCH 38/48] make regen-global-objects

---
 Include/internal/pycore_global_objects_fini_generated.h | 1 +
 Include/internal/pycore_global_strings.h                | 1 +
 Include/internal/pycore_runtime_init_generated.h        | 1 +
 Include/internal/pycore_unicodeobject_generated.h       | 3 +++
 4 files changed, 6 insertions(+)

diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h
index e8b62bd0dcd369..afba88501f08b8 100644
--- a/Include/internal/pycore_global_objects_fini_generated.h
+++ b/Include/internal/pycore_global_objects_fini_generated.h
@@ -977,6 +977,7 @@ _PyStaticObjects_CheckRefcnt(PyInterpreterState *interp) {
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(h));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(handle));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(handle_seq));
+    _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(has_location));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(hash_name));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(header));
     _PyStaticObject_CheckRefcnt((PyObject *)&_Py_ID(headers));
diff --git a/Include/internal/pycore_global_strings.h b/Include/internal/pycore_global_strings.h
index b41f5c8952021e..38b3f11191ac02 100644
--- a/Include/internal/pycore_global_strings.h
+++ b/Include/internal/pycore_global_strings.h
@@ -466,6 +466,7 @@ struct _Py_global_strings {
         STRUCT_FOR_ID(h)
         STRUCT_FOR_ID(handle)
         STRUCT_FOR_ID(handle_seq)
+        STRUCT_FOR_ID(has_location)
         STRUCT_FOR_ID(hash_name)
         STRUCT_FOR_ID(header)
         STRUCT_FOR_ID(headers)
diff --git a/Include/internal/pycore_runtime_init_generated.h b/Include/internal/pycore_runtime_init_generated.h
index 016eae02a2103d..7b898bc91aba0d 100644
--- a/Include/internal/pycore_runtime_init_generated.h
+++ b/Include/internal/pycore_runtime_init_generated.h
@@ -975,6 +975,7 @@ extern "C" {
     INIT_ID(h), \
     INIT_ID(handle), \
     INIT_ID(handle_seq), \
+    INIT_ID(has_location), \
     INIT_ID(hash_name), \
     INIT_ID(header), \
     INIT_ID(headers), \
diff --git a/Include/internal/pycore_unicodeobject_generated.h b/Include/internal/pycore_unicodeobject_generated.h
index 64c4cf8c077056..518207596e3578 100644
--- a/Include/internal/pycore_unicodeobject_generated.h
+++ b/Include/internal/pycore_unicodeobject_generated.h
@@ -1239,6 +1239,9 @@ _PyUnicode_InitStaticStrings(PyInterpreterState *interp) {
     string = &_Py_ID(handle_seq);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);
+    string = &_Py_ID(has_location);
+    assert(_PyUnicode_CheckConsistency(string, 1));
+    _PyUnicode_InternInPlace(interp, &string);
     string = &_Py_ID(hash_name);
     assert(_PyUnicode_CheckConsistency(string, 1));
     _PyUnicode_InternInPlace(interp, &string);

From 786b74e170e33c8a6bad61b6028d07338c3b674d Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 00:25:40 -0800
Subject: [PATCH 39/48] fix spacing

---
 Lib/test/test_import/__init__.py | 4 ++--
 Objects/moduleobject.c           | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index ba574c87347893..d9f73794e51333 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -798,7 +798,7 @@ def test_script_shadowing_stdlib(self):
             expected_error = (
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
-                rb"same name as the standard library module named 'fractions'"
+                rb"same name as the standard library module named 'fractions' "
                 rb"and takes precedence over it on sys.path\)"
             )
 
@@ -936,7 +936,7 @@ def test_script_shadowing_stdlib_sys_path_modification(self):
             expected_error = (
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
-                rb"same name as the standard library module named 'fractions'"
+                rb"same name as the standard library module named 'fractions' "
                 rb"and takes precedence over it on sys.path\)"
             )
 
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 85bd4c336f8f51..02d0aded51b82b 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -948,7 +948,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
         PyErr_Format(PyExc_AttributeError,
                     "module '%U' has no attribute '%U' "
                     "(consider renaming '%U' since it has the same "
-                    "name as the standard library module named '%U'"
+                    "name as the standard library module named '%U' "
                     "and takes precedence over it on sys.path)",
                     mod_name, name, origin, mod_name);
     } else {

From d7f1bc089b222f4993c206d9369e86cff8bc0215 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 00:51:54 -0800
Subject: [PATCH 40/48] Revert "remove explicit safe path check"

This reverts commit 3ec37d19b2b80aa093f1358254e895668981e2c2.
---
 Objects/moduleobject.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 02d0aded51b82b..6895df01b16ca9 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -825,12 +825,9 @@ _is_module_possibly_shadowing(PyObject *origin)
         return 0;
     }
     const PyConfig *config = _Py_GetConfig();
-    // sys.path[0] or os.getcwd()
-    wchar_t *sys_path_0 = config->sys_path_0;
-    if (sys_path_0 == NULL) {
+    if (config->safe_path) {
         return 0;
     }
-    assert(!config->safe_path);
 
     // os.path.dirname(origin)
     wchar_t origin_dirname[MAXPATHLEN + 1];
@@ -847,6 +844,12 @@ _is_module_possibly_shadowing(PyObject *origin)
     }
     *sep = L'\0';
 
+    // sys.path[0] or os.getcwd()
+    wchar_t *sys_path_0 = config->sys_path_0;
+    if (!sys_path_0) {
+        return 0;
+    }
+
     wchar_t sys_path_0_buf[MAXPATHLEN];
     if (sys_path_0[0] == L'\0') {
         // if sys.path[0] == "", treat it as if it were the current directory

From e55576dd0bbbcad2c65a0370e6749d1eb530fe21 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 11:30:38 -0800
Subject: [PATCH 41/48] test the no origin case

---
 Lib/test/test_import/__init__.py | 18 ++++++++++++++++++
 Objects/moduleobject.c           |  1 +
 2 files changed, 19 insertions(+)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index d9f73794e51333..bf4de6b3c3e6db 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -928,6 +928,24 @@ class substr(str):
                 ],
             )
 
+            with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                f.write("""
+import fractions
+fractions.shadowing_module
+del fractions.__spec__.origin
+try:
+    fractions.Fraction
+except AttributeError as e:
+    print(str(e))
+""")
+
+            popen = script_helper.spawn_python("main.py", cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertEqual(
+                stdout.splitlines(),
+                [b"module 'fractions' has no attribute 'Fraction'"],
+            )
+
     def test_script_shadowing_stdlib_sys_path_modification(self):
         with os_helper.temp_dir() as tmp:
             with open(os.path.join(tmp, "fractions.py"), "w", encoding='utf-8') as f:
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 6895df01b16ca9..e3d3601e498bd0 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -804,6 +804,7 @@ _get_file_origin_from_spec(PyObject *spec, PyObject **origin)
     if (rc <= 0) {
         return rc;
     }
+    assert(origin != NULL);
     if (!PyUnicode_Check(*origin)) {
         Py_DECREF(*origin);
         *origin = NULL;

From a388887041ac90bcc405714f9f6ee8366d6e0b53 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 11:36:42 -0800
Subject: [PATCH 42/48] output param feedback

---
 Objects/moduleobject.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index e3d3601e498bd0..c987b72cc52d41 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -787,7 +787,7 @@ _PyModuleSpec_IsUninitializedSubmodule(PyObject *spec, PyObject *name)
 }
 
 static int
-_get_file_origin_from_spec(PyObject *spec, PyObject **origin)
+_get_file_origin_from_spec(PyObject *spec, PyObject **p_origin)
 {
     PyObject *has_location = NULL;
     int rc = PyObject_GetOptionalAttr(spec, &_Py_ID(has_location), &has_location);
@@ -800,16 +800,18 @@ _get_file_origin_from_spec(PyObject *spec, PyObject **origin)
         return rc;
     }
     // has_location is true, so origin is a location
-    rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), origin);
+    PyObject *origin = NULL;
+    rc = PyObject_GetOptionalAttr(spec, &_Py_ID(origin), &origin);
     if (rc <= 0) {
         return rc;
     }
     assert(origin != NULL);
-    if (!PyUnicode_Check(*origin)) {
-        Py_DECREF(*origin);
-        *origin = NULL;
+    if (!PyUnicode_Check(origin)) {
+        Py_DECREF(origin);
+        *p_origin = NULL;
         return 0;
     }
+    *p_origin = origin;
     return 1;
 }
 

From 3d360324f082bb48fea8b456b34982f7989d90e6 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 11:38:50 -0800
Subject: [PATCH 43/48] test non-str origin

---
 Lib/test/test_import/__init__.py | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index bf4de6b3c3e6db..9fe9b918392f50 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -933,6 +933,12 @@ class substr(str):
 import fractions
 fractions.shadowing_module
 del fractions.__spec__.origin
+try:
+    fractions.Fraction
+except AttributeError as e:
+    print(str(e))
+
+fractions.__spec__.origin = 0
 try:
     fractions.Fraction
 except AttributeError as e:
@@ -943,7 +949,10 @@ class substr(str):
             stdout, stderr = popen.communicate()
             self.assertEqual(
                 stdout.splitlines(),
-                [b"module 'fractions' has no attribute 'Fraction'"],
+                [
+                    b"module 'fractions' has no attribute 'Fraction'",
+                    b"module 'fractions' has no attribute 'Fraction'"
+                ],
             )
 
     def test_script_shadowing_stdlib_sys_path_modification(self):

From 616ced27256b0616b40495a89fed56d68136d40c Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 11:42:58 -0800
Subject: [PATCH 44/48] add comment about module.__file__

---
 Objects/moduleobject.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index c987b72cc52d41..2f6ff9ea38ac80 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -794,6 +794,9 @@ _get_file_origin_from_spec(PyObject *spec, PyObject **p_origin)
     if (rc <= 0) {
         return rc;
     }
+    // If origin is not a location, or doesn't exist, or is not a str), we could consider falling
+    // back to module.__file__. But the cases in which module.__file__ is not __spec__.origin
+    // are cases in which we probably shouldn't be guessing.
     rc = PyObject_IsTrue(has_location);
     Py_DECREF(has_location);
     if (rc <= 0) {

From afbcd403f56ac47e120895e7f848c5a5db0e1c61 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 12:31:22 -0800
Subject: [PATCH 45/48] test package shadowing module

---
 Lib/test/test_import/__init__.py | 32 ++++++++++++++++++++++++++++++++
 Objects/moduleobject.c           | 26 ++++++++++++++++++--------
 2 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index 9fe9b918392f50..eb9ce1007d2e9f 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -835,6 +835,38 @@ def test_script_shadowing_stdlib(self):
             stdout, stderr = popen.communicate()
             self.assertEqual(stdout, b'')  # no error
 
+    def test_package_shadowing_stdlib_module(self):
+        with os_helper.temp_dir() as tmp:
+            os.mkdir(os.path.join(tmp, "fractions"))
+            with open(os.path.join(tmp, "fractions", "__init__.py"), "w", encoding='utf-8') as f:
+                f.write("shadowing_module = True")
+            with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
+                f.write("""
+import fractions
+fractions.shadowing_module
+fractions.Fraction
+""")
+
+            expected_error = (
+                rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
+                rb"\(consider renaming '.*fractions.__init__.py' since it has the "
+                rb"same name as the standard library module named 'fractions' "
+                rb"and takes precedence over it on sys.path\)"
+            )
+
+            popen = script_helper.spawn_python(os.path.join(tmp, "main.py"), cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            popen = script_helper.spawn_python('-m', 'main', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, expected_error)
+
+            # and there's no shadowing at all when using -P
+            popen = script_helper.spawn_python('-P', 'main.py', cwd=tmp)
+            stdout, stderr = popen.communicate()
+            self.assertRegex(stdout, b"module 'fractions' has no attribute 'shadowing_module'")
+
     def test_script_shadowing_third_party(self):
         with os_helper.temp_dir() as tmp:
             with open(os.path.join(tmp, "numpy.py"), "w", encoding='utf-8') as f:
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 2f6ff9ea38ac80..da8ca9344f72d6 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -824,30 +824,40 @@ _is_module_possibly_shadowing(PyObject *origin)
     // origin must be a unicode subtype
     // Returns 1 if the module at origin could be shadowing a module of the
     // same name later in the module search path. The condition we check is basically:
-    // not sys.flags.safe_path and os.path.dirname(origin) == (sys.path[0] or os.getcwd())
+    // root = os.path.dirname(origin.removesuffix(os.sep + "__init__.py"))
+    // return not sys.flags.safe_path and root == (sys.path[0] or os.getcwd())
     // Returns 0 otherwise (or if we aren't sure)
     // Returns -1 if an error occurred that should be propagated
     if (origin == NULL) {
         return 0;
     }
+
+    // not sys.flags.safe_path
     const PyConfig *config = _Py_GetConfig();
     if (config->safe_path) {
         return 0;
     }
 
-    // os.path.dirname(origin)
-    wchar_t origin_dirname[MAXPATHLEN + 1];
-    Py_ssize_t size = PyUnicode_AsWideChar(origin, origin_dirname, MAXPATHLEN);
+    // root = os.path.dirname(origin.removesuffix(os.sep + "__init__.py"))
+    wchar_t root[MAXPATHLEN + 1];
+    Py_ssize_t size = PyUnicode_AsWideChar(origin, root, MAXPATHLEN);
     if (size < 0) {
         return -1;
     }
     assert(size <= MAXPATHLEN);
-    origin_dirname[size] = L'\0';
+    root[size] = L'\0';
 
-    wchar_t *sep = wcsrchr(origin_dirname, SEP);
-    if (!sep) {
+    wchar_t *sep = wcsrchr(root, SEP);
+    if (sep == NULL) {
         return 0;
     }
+    if (wcscmp(sep + 1, L"__init__.py") == 0) {
+        *sep = L'\0';
+        sep = wcsrchr(root, SEP);
+        if (sep == NULL) {
+            return 0;
+        }
+    }
     *sep = L'\0';
 
     // sys.path[0] or os.getcwd()
@@ -865,7 +875,7 @@ _is_module_possibly_shadowing(PyObject *origin)
         sys_path_0 = sys_path_0_buf;
     }
 
-    int result = wcscmp(sys_path_0, origin_dirname) == 0;
+    int result = wcscmp(sys_path_0, root) == 0;
     return result;
 }
 

From 2890b6b18da4aae64d67d50292d24278d6847287 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 8 Mar 2024 14:09:12 -0800
Subject: [PATCH 46/48] feedback

---
 Objects/moduleobject.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index da8ca9344f72d6..56c2b94a97f607 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -811,7 +811,6 @@ _get_file_origin_from_spec(PyObject *spec, PyObject **p_origin)
     assert(origin != NULL);
     if (!PyUnicode_Check(origin)) {
         Py_DECREF(origin);
-        *p_origin = NULL;
         return 0;
     }
     *p_origin = origin;
@@ -851,6 +850,7 @@ _is_module_possibly_shadowing(PyObject *origin)
     if (sep == NULL) {
         return 0;
     }
+    // If it's a package then we need to look one directory further up
     if (wcscmp(sep + 1, L"__init__.py") == 0) {
         *sep = L'\0';
         sep = wcsrchr(root, SEP);

From 1d65725147d996a88904d238f895d1c919846251 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 1 Apr 2024 11:41:12 -0700
Subject: [PATCH 47/48] try another error message variation

---
 Doc/whatsnew/3.13.rst            | 2 +-
 Lib/test/test_import/__init__.py | 8 ++++----
 Objects/moduleobject.c           | 2 +-
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index e0b0447ecf27e1..901cc98838ad45 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -114,7 +114,7 @@ Improved Error Messages
       File "/home/random.py", line 1, in <module>
         import random; print(random.randint(5))
                             ^^^^^^^^^^^^^^
-    AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random'and takes precedence over it on sys.path)
+    AttributeError: module 'random' has no attribute 'randint' (consider renaming '/home/random.py' since it has the same name as the standard library module named 'random' and the import system gives it precedence)
 
   Similarly, if a script has the same name as a third-party
   module it attempts to import, and this results in errors,
diff --git a/Lib/test/test_import/__init__.py b/Lib/test/test_import/__init__.py
index eb9ce1007d2e9f..28eaaf881010e7 100644
--- a/Lib/test/test_import/__init__.py
+++ b/Lib/test/test_import/__init__.py
@@ -799,7 +799,7 @@ def test_script_shadowing_stdlib(self):
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
                 rb"same name as the standard library module named 'fractions' "
-                rb"and takes precedence over it on sys.path\)"
+                rb"and the import system gives it precedence\)"
             )
 
             popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"), cwd=tmp)
@@ -822,7 +822,7 @@ def test_script_shadowing_stdlib(self):
             tmp_child = os.path.join(tmp, "child")
             os.mkdir(tmp_child)
 
-            # test the logic in with different cwd
+            # test the logic with different cwd
             popen = script_helper.spawn_python(os.path.join(tmp, "fractions.py"), cwd=tmp_child)
             stdout, stderr = popen.communicate()
             self.assertRegex(stdout, expected_error)
@@ -851,7 +851,7 @@ def test_package_shadowing_stdlib_module(self):
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.__init__.py' since it has the "
                 rb"same name as the standard library module named 'fractions' "
-                rb"and takes precedence over it on sys.path\)"
+                rb"and the import system gives it precedence\)"
             )
 
             popen = script_helper.spawn_python(os.path.join(tmp, "main.py"), cwd=tmp)
@@ -996,7 +996,7 @@ def test_script_shadowing_stdlib_sys_path_modification(self):
                 rb"AttributeError: module 'fractions' has no attribute 'Fraction' "
                 rb"\(consider renaming '.*fractions.py' since it has the "
                 rb"same name as the standard library module named 'fractions' "
-                rb"and takes precedence over it on sys.path\)"
+                rb"and the import system gives it precedence\)"
             )
 
             with open(os.path.join(tmp, "main.py"), "w", encoding='utf-8') as f:
diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 56c2b94a97f607..195d4d9bfff8f8 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -968,7 +968,7 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
                     "module '%U' has no attribute '%U' "
                     "(consider renaming '%U' since it has the same "
                     "name as the standard library module named '%U' "
-                    "and takes precedence over it on sys.path)",
+                    "and the import system gives it precedence)",
                     mod_name, name, origin, mod_name);
     } else {
         int rc = _PyModuleSpec_IsInitializing(spec);

From 300c557d969ef946157a6cb226fa00854b8d73c6 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Mon, 22 Apr 2024 15:42:35 -0700
Subject: [PATCH 48/48] style nits

---
 Objects/moduleobject.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 195d4d9bfff8f8..eba708946215f6 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -943,20 +943,20 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
     }
 
     PyObject *origin = NULL;
-    if (_get_file_origin_from_spec(spec, &origin) == -1) {
+    if (_get_file_origin_from_spec(spec, &origin) < 0) {
         goto done;
     }
 
     int is_possibly_shadowing = _is_module_possibly_shadowing(origin);
-    if (is_possibly_shadowing == -1) {
+    if (is_possibly_shadowing < 0) {
         goto done;
     }
     int is_possibly_shadowing_stdlib = 0;
-    if (is_possibly_shadowing == 1) {
+    if (is_possibly_shadowing) {
         PyObject *stdlib_modules = PySys_GetObject("stdlib_module_names");
         if (stdlib_modules && PyAnySet_Check(stdlib_modules)) {
             is_possibly_shadowing_stdlib = PySet_Contains(stdlib_modules, mod_name);
-            if (is_possibly_shadowing_stdlib == -1) {
+            if (is_possibly_shadowing_stdlib < 0) {
                 goto done;
             }
         }
@@ -970,7 +970,8 @@ _Py_module_getattro_impl(PyModuleObject *m, PyObject *name, int suppress)
                     "name as the standard library module named '%U' "
                     "and the import system gives it precedence)",
                     mod_name, name, origin, mod_name);
-    } else {
+    }
+    else {
         int rc = _PyModuleSpec_IsInitializing(spec);
         if (rc > 0) {
             if (is_possibly_shadowing) {