Avoid importing submodules sharing names with standard library modules (#2702)

Author: jacobtylerwalls

ChangeLog

@@ -37,7 +37,9 @@ What's New in astroid 3.3.10?
 =============================
 Release date: TBA
 
+* Avoid importing submodules sharing names with standard library modules.
 
+  Closes #2684
 
 
 What's New in astroid 3.3.9?

astroid/interpreter/_import/spec.py

@@ -174,7 +174,7 @@ def find_module(
             # module. Note that `find_spec` actually imports parent modules, so we want to make
             # sure we only run this code for stuff that can be expected to be frozen. For now
             # this is only stdlib.
-            if modname in sys.stdlib_module_names or (
+            if (modname in sys.stdlib_module_names and not processed) or (
                 processed and processed[0] in sys.stdlib_module_names
             ):
                 try:

tests/test_modutils.py

@@ -628,3 +628,18 @@ def test_find_setuptools_pep660_editable_install():
     with unittest.mock.patch.object(sys, "meta_path", new=[_EditableFinder]):
         assert spec.find_spec(["example"])
         assert spec.find_spec(["example", "subpackage"])
+
+
+def test_no_import_done_for_submodule_sharing_std_lib_name() -> None:
+    sys.path.insert(0, resources.find("data"))
+    try:
+        with pytest.raises(ImportError):
+            spec._find_spec_with_path(
+                [resources.find("data")],
+                "trace",
+                ("divide_by_zero", "trace"),
+                ("divide_by_zero",),
+                resources.find("data/divide_by_zero"),
+            )
+    finally:
+        sys.path.pop(0)

tests/testdata/python3/data/divide_by_zero.py

@@ -0,0 +1 @@
+1 / 0