Prevent special case for virtualenv's patching of distutils from catching other submodules (#1544)

Author: jacobtylerwalls

ChangeLog

@@ -18,6 +18,11 @@ Release date: TBA
 * Rename ``ModuleSpec`` -> ``module_type`` constructor parameter to match attribute
   name and improve typing. Use ``type`` instead.
 
+* Fix a bug where in attempting to handle the patching of ``distutils`` by ``virtualenv``,
+  library submodules called ``distutils`` (e.g. ``numpy.distutils``) were included also.
+
+  Refs PyCQA/pylint#6497
+
 
 What's New in astroid 2.11.5?
 =============================

astroid/interpreter/_import/spec.py

@@ -14,6 +14,8 @@
 from pathlib import Path
 from typing import List, NamedTuple, Optional, Sequence, Tuple
 
+from astroid.modutils import EXT_LIB_DIRS
+
 from . import util
 
 
@@ -150,7 +152,10 @@ def contribute_to_path(self, spec, processed):
                 for p in sys.path
                 if os.path.isdir(os.path.join(p, *processed))
             ]
-        elif spec.name == "distutils":
+        elif spec.name == "distutils" and not any(
+            spec.location.lower().startswith(ext_lib_dir.lower())
+            for ext_lib_dir in EXT_LIB_DIRS
+        ):
             # virtualenv below 20.0 patches distutils in an unexpected way
             # so we just find the location of distutils that will be
             # imported to avoid spurious import-error messages

tests/unittest_regrtest.py

@@ -81,6 +81,23 @@ def test_numpy_crash(self):
         inferred = callfunc.inferred()
         self.assertEqual(len(inferred), 1)
 
+    @unittest.skipUnless(HAS_NUMPY, "Needs numpy")
+    def test_numpy_distutils(self):
+        """Special handling of virtualenv's patching of distutils shouldn't interfere
+        with numpy.distutils.
+
+        PY312_PLUS -- This test will likely become unnecessary when Python 3.12 is
+        numpy's minimum version. (numpy.distutils will be removed then.)
+        """
+        node = extract_node(
+            """
+from numpy.distutils.misc_util import is_sequence
+is_sequence("ABC") #@
+"""
+        )
+        inferred = node.inferred()
+        self.assertIsInstance(inferred[0], nodes.Const)
+
     def test_nameconstant(self) -> None:
         # used to fail for Python 3.4
         builder = AstroidBuilder()