diff -Nru importlib-resources-5.1.0/CHANGES.rst importlib-resources-5.1.2/CHANGES.rst
--- importlib-resources-5.1.0/CHANGES.rst	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/CHANGES.rst	2021-03-04 18:46:52.000000000 +0000
@@ -1,3 +1,34 @@
+v5.1.2
+======
+
+* Re-release with changes from 5.0.4.
+
+v5.0.4
+======
+
+* Fixed non-hermetic test in test_reader, revealed by
+  GH-24670.
+
+v5.1.1
+======
+
+* Re-release with changes from 5.0.3.
+
+v5.0.3
+======
+
+* Simplified DegenerateFiles.Path.
+
+v5.0.2
+======
+
+* #214: Added ``_adapters`` module to ensure that degenerate
+  ``files`` behavior can be made available for legacy loaders
+  whose resource readers don't implement it. Fixes issue where
+  backport compatibility module was masking this fallback
+  behavior only to discover the defect when applying changes to
+  CPython.
+
 v5.1.0
 ======
 
diff -Nru importlib-resources-5.1.0/debian/changelog importlib-resources-5.1.2/debian/changelog
--- importlib-resources-5.1.0/debian/changelog	2021-01-23 19:48:49.000000000 +0000
+++ importlib-resources-5.1.2/debian/changelog	2021-03-08 11:39:49.000000000 +0000
@@ -1,3 +1,14 @@
+importlib-resources (5.1.2-1) unstable; urgency=medium
+
+  [ Jonas Meurer ]
+  * New upstream release 5.1.2
+
+  [ Debian Janitor ]
+  * Set upstream metadata fields: Bug-Database, Bug-Submit, Repository,
+    Repository-Browse.
+
+ -- Jonas Meurer <jonas@freesources.org>  Mon, 08 Mar 2021 12:39:49 +0100
+
 importlib-resources (5.1.0-1) unstable; urgency=medium
 
   * New upstream release 5.1.0
diff -Nru importlib-resources-5.1.0/debian/upstream/metadata importlib-resources-5.1.2/debian/upstream/metadata
--- importlib-resources-5.1.0/debian/upstream/metadata	1970-01-01 00:00:00.000000000 +0000
+++ importlib-resources-5.1.2/debian/upstream/metadata	2021-03-08 11:39:49.000000000 +0000
@@ -0,0 +1,5 @@
+---
+Bug-Database: https://github.com/python/importlib_resources/issues
+Bug-Submit: https://github.com/python/importlib_resources/issues/new
+Repository: https://github.com/python/importlib_resources.git
+Repository-Browse: https://github.com/python/importlib_resources
diff -Nru importlib-resources-5.1.0/.editorconfig importlib-resources-5.1.2/.editorconfig
--- importlib-resources-5.1.0/.editorconfig	1970-01-01 00:00:00.000000000 +0000
+++ importlib-resources-5.1.2/.editorconfig	2021-03-04 18:46:52.000000000 +0000
@@ -0,0 +1,15 @@
+root = true
+
+[*]
+charset = utf-8
+indent_style = tab
+indent_size = 4
+insert_final_newline = true
+end_of_line = lf
+
+[*.py]
+indent_style = space
+
+[*.{yml,yaml}]
+indent_style = space
+indent_size = 2
diff -Nru importlib-resources-5.1.0/importlib_resources/_adapters.py importlib-resources-5.1.2/importlib_resources/_adapters.py
--- importlib-resources-5.1.0/importlib_resources/_adapters.py	1970-01-01 00:00:00.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources/_adapters.py	2021-03-04 18:46:52.000000000 +0000
@@ -0,0 +1,82 @@
+from contextlib import suppress
+
+from . import abc
+
+
+class SpecLoaderAdapter:
+    """
+    Adapt a package spec to adapt the underlying loader.
+    """
+
+    def __init__(self, spec, adapter=lambda spec: spec.loader):
+        self.spec = spec
+        self.loader = adapter(spec)
+
+    def __getattr__(self, name):
+        return getattr(self.spec, name)
+
+
+class TraversableResourcesLoader:
+    """
+    Adapt a loader to provide TraversableResources.
+    """
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    def get_resource_reader(self, name):
+        return DegenerateFiles(self.spec)._native()
+
+
+class DegenerateFiles:
+    """
+    Adapter for an existing or non-existant resource reader
+    to provide a degenerate .files().
+    """
+
+    class Path(abc.Traversable):
+        def iterdir(self):
+            return iter(())
+
+        def is_dir(self):
+            return False
+
+        is_file = exists = is_dir  # type: ignore
+
+        def joinpath(self, other):
+            return DegenerateFiles.Path()
+
+        def name(self):
+            return ''
+
+        def open(self):
+            raise ValueError()
+
+    def __init__(self, spec):
+        self.spec = spec
+
+    @property
+    def _reader(self):
+        with suppress(AttributeError):
+            return self.spec.loader.get_resource_reader(self.spec.name)
+
+    def _native(self):
+        """
+        Return the native reader if it supports files().
+        """
+        reader = self._reader
+        return reader if hasattr(reader, 'files') else self
+
+    def __getattr__(self, attr):
+        return getattr(self._reader, attr)
+
+    def files(self):
+        return DegenerateFiles.Path()
+
+
+def wrap_spec(package):
+    """
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
+    """
+    return SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
diff -Nru importlib-resources-5.1.0/importlib_resources/_common.py importlib-resources-5.1.2/importlib_resources/_common.py
--- importlib-resources-5.1.0/importlib_resources/_common.py	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources/_common.py	2021-03-04 18:46:52.000000000 +0000
@@ -9,7 +9,7 @@
 from typing import Union, Any, Optional
 from .abc import ResourceReader
 
-from ._compat import package_spec
+from ._compat import wrap_spec
 
 Package = Union[types.ModuleType, str]
 
@@ -63,7 +63,7 @@
     Raise an exception if the resolved module is not a package.
     """
     resolved = resolve(package)
-    if package_spec(resolved).submodule_search_locations is None:
+    if wrap_spec(resolved).submodule_search_locations is None:
         raise TypeError('{!r} is not a package'.format(package))
     return resolved
 
@@ -73,7 +73,7 @@
     Return a Traversable object for the given package.
 
     """
-    spec = package_spec(package)
+    spec = wrap_spec(package)
     reader = spec.loader.get_resource_reader(spec.name)
     return reader.files()
 
diff -Nru importlib-resources-5.1.0/importlib_resources/_compat.py importlib-resources-5.1.2/importlib_resources/_compat.py
--- importlib-resources-5.1.0/importlib_resources/_compat.py	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources/_compat.py	2021-03-04 18:46:52.000000000 +0000
@@ -1,9 +1,10 @@
+# flake8: noqa
+
 import abc
 import sys
+import pathlib
 from contextlib import suppress
 
-# flake8: noqa
-
 try:
     from zipfile import Path as ZipPath  # type: ignore
 except ImportError:
@@ -24,16 +25,7 @@
     Protocol = abc.ABC  # type: ignore
 
 
-class TraversableResourcesAdapter:
-    def __init__(self, spec):
-        self.spec = spec
-        self.loader = LoaderAdapter(spec)
-
-    def __getattr__(self, name):
-        return getattr(self.spec, name)
-
-
-class LoaderAdapter:
+class TraversableResourcesLoader:
     """
     Adapt loaders to provide TraversableResources and other
     compatibility.
@@ -47,8 +39,7 @@
         return self.spec.origin
 
     def get_resource_reader(self, name):
-        # Python < 3.9
-        from . import readers
+        from . import readers, _adapters
 
         def _zip_reader(spec):
             with suppress(AttributeError):
@@ -66,6 +57,10 @@
             reader = _available_reader(spec)
             return reader if hasattr(reader, 'files') else None
 
+        def _file_reader(spec):
+            if pathlib.Path(self.path).exists():
+                return readers.FileReader(self)
+
         return (
             # native reader if it supplies 'files'
             _native_reader(self.spec)
@@ -77,14 +72,16 @@
             _namespace_reader(self.spec)
             or
             # local FileReader
-            readers.FileReader(self)
+            _file_reader(self.spec)
+            or _adapters.DegenerateFiles(self.spec)
         )
 
 
-def package_spec(package):
+def wrap_spec(package):
     """
-    Construct a minimal package spec suitable for
-    matching the interfaces this library relies upon
-    in later Python versions.
+    Construct a package spec with traversable compatibility
+    on the spec/loader/reader.
     """
-    return TraversableResourcesAdapter(package.__spec__)
+    from . import _adapters
+
+    return _adapters.SpecLoaderAdapter(package.__spec__, TraversableResourcesLoader)
diff -Nru importlib-resources-5.1.0/importlib_resources/tests/test_reader.py importlib-resources-5.1.2/importlib_resources/tests/test_reader.py
--- importlib-resources-5.1.0/importlib_resources/tests/test_reader.py	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources/tests/test_reader.py	2021-03-04 18:46:52.000000000 +0000
@@ -1,5 +1,6 @@
 import os.path
 import sys
+import pathlib
 import unittest
 
 from importlib import import_module
@@ -9,7 +10,8 @@
 class MultiplexedPathTest(unittest.TestCase):
     @classmethod
     def setUpClass(cls):
-        cls.folder = os.path.abspath(os.path.join(__file__, '..', 'namespacedata01'))
+        path = pathlib.Path(__file__).parent / 'namespacedata01'
+        cls.folder = str(path)
 
     def test_init_no_paths(self):
         with self.assertRaises(FileNotFoundError):
@@ -83,9 +85,15 @@
 
 
 class NamespaceReaderTest(unittest.TestCase):
+    site_dir = str(pathlib.Path(__file__).parent)
+
     @classmethod
     def setUpClass(cls):
-        sys.path.append(os.path.abspath(os.path.join(__file__, '..')))
+        sys.path.append(cls.site_dir)
+
+    @classmethod
+    def tearDownClass(cls):
+        sys.path.remove(cls.site_dir)
 
     def test_init_error(self):
         with self.assertRaises(ValueError):
diff -Nru importlib-resources-5.1.0/importlib_resources/tests/test_resource.py importlib-resources-5.1.2/importlib_resources/tests/test_resource.py
--- importlib-resources-5.1.0/importlib_resources/tests/test_resource.py	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources/tests/test_resource.py	2021-03-04 18:46:52.000000000 +0000
@@ -1,9 +1,8 @@
-import os.path
 import sys
 import unittest
 import importlib_resources as resources
 import uuid
-from pathlib import Path
+import pathlib
 
 from . import data01
 from . import zipdata01, zipdata02
@@ -150,10 +149,10 @@
         modules = import_helper.modules_setup()
         self.addCleanup(import_helper.modules_cleanup, *modules)
 
-        data_path = Path(self.ZIP_MODULE.__file__)
+        data_path = pathlib.Path(self.ZIP_MODULE.__file__)
         data_dir = data_path.parent
         self.source_zip_path = data_dir / 'ziptestdata.zip'
-        self.zip_path = Path('{}.zip'.format(uuid.uuid4())).absolute()
+        self.zip_path = pathlib.Path('{}.zip'.format(uuid.uuid4())).absolute()
         self.zip_path.write_bytes(self.source_zip_path.read_bytes())
         sys.path.append(str(self.zip_path))
         self.data = import_module('ziptestdata')
@@ -216,9 +215,15 @@
 
 
 class ResourceFromNamespaceTest01(unittest.TestCase):
+    site_dir = str(pathlib.Path(__file__).parent)
+
     @classmethod
     def setUpClass(cls):
-        sys.path.append(os.path.abspath(os.path.join(__file__, '..')))
+        sys.path.append(cls.site_dir)
+
+    @classmethod
+    def tearDownClass(cls):
+        sys.path.remove(cls.site_dir)
 
     def test_is_submodule_resource(self):
         self.assertTrue(
diff -Nru importlib-resources-5.1.0/importlib_resources.egg-info/PKG-INFO importlib-resources-5.1.2/importlib_resources.egg-info/PKG-INFO
--- importlib-resources-5.1.0/importlib_resources.egg-info/PKG-INFO	2021-01-19 03:22:35.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources.egg-info/PKG-INFO	2021-03-04 18:47:24.000000000 +0000
@@ -1,6 +1,6 @@
 Metadata-Version: 2.1
 Name: importlib-resources
-Version: 5.1.0
+Version: 5.1.2
 Summary: Read resources from Python packages
 Home-page: https://github.com/python/importlib_resources
 Author: Barry Warsaw
diff -Nru importlib-resources-5.1.0/importlib_resources.egg-info/requires.txt importlib-resources-5.1.2/importlib_resources.egg-info/requires.txt
--- importlib-resources-5.1.0/importlib_resources.egg-info/requires.txt	2021-01-19 03:22:35.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources.egg-info/requires.txt	2021-03-04 18:47:24.000000000 +0000
@@ -8,7 +8,7 @@
 rst.linker>=1.9
 
 [testing]
-pytest!=3.7.3,>=3.5
+pytest>=4.6
 pytest-checkdocs>=1.2.3
 pytest-flake8
 pytest-cov
diff -Nru importlib-resources-5.1.0/importlib_resources.egg-info/SOURCES.txt importlib-resources-5.1.2/importlib_resources.egg-info/SOURCES.txt
--- importlib-resources-5.1.0/importlib_resources.egg-info/SOURCES.txt	2021-01-19 03:22:35.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources.egg-info/SOURCES.txt	2021-03-04 18:47:24.000000000 +0000
@@ -1,4 +1,5 @@
 .coveragerc
+.editorconfig
 .flake8
 .gitattributes
 .gitignore
@@ -23,6 +24,7 @@
 docs/migration.rst
 docs/using.rst
 importlib_resources/__init__.py
+importlib_resources/_adapters.py
 importlib_resources/_common.py
 importlib_resources/_compat.py
 importlib_resources/_py3.py
diff -Nru importlib-resources-5.1.0/importlib_resources.egg-info/top_level.txt importlib-resources-5.1.2/importlib_resources.egg-info/top_level.txt
--- importlib-resources-5.1.0/importlib_resources.egg-info/top_level.txt	2021-01-19 03:22:35.000000000 +0000
+++ importlib-resources-5.1.2/importlib_resources.egg-info/top_level.txt	2021-03-04 18:47:24.000000000 +0000
@@ -1,2 +1 @@
-dist
 importlib_resources
diff -Nru importlib-resources-5.1.0/PKG-INFO importlib-resources-5.1.2/PKG-INFO
--- importlib-resources-5.1.0/PKG-INFO	2021-01-19 03:22:35.562694500 +0000
+++ importlib-resources-5.1.2/PKG-INFO	2021-03-04 18:47:24.554228300 +0000
@@ -1,6 +1,6 @@
 Metadata-Version: 2.1
 Name: importlib_resources
-Version: 5.1.0
+Version: 5.1.2
 Summary: Read resources from Python packages
 Home-page: https://github.com/python/importlib_resources
 Author: Barry Warsaw
diff -Nru importlib-resources-5.1.0/pytest.ini importlib-resources-5.1.2/pytest.ini
--- importlib-resources-5.1.0/pytest.ini	2021-01-19 03:22:15.000000000 +0000
+++ importlib-resources-5.1.2/pytest.ini	2021-03-04 18:46:52.000000000 +0000
@@ -5,5 +5,3 @@
 # workaround for warning pytest-dev/pytest#6178
 junit_family=xunit2
 filterwarnings=
-    # https://github.com/pytest-dev/pytest/issues/6928
-    ignore:direct construction of .*Item has been deprecated:DeprecationWarning
diff -Nru importlib-resources-5.1.0/setup.cfg importlib-resources-5.1.2/setup.cfg
--- importlib-resources-5.1.0/setup.cfg	2021-01-19 03:22:35.562694500 +0000
+++ importlib-resources-5.1.2/setup.cfg	2021-03-04 18:47:24.558228300 +0000
@@ -28,12 +28,13 @@
 [options.packages.find]
 exclude = 
 	build*
+	dist*
 	docs*
 	tests*
 
 [options.extras_require]
 testing = 
-	pytest >= 3.5, !=3.7.3
+	pytest >= 4.6
 	pytest-checkdocs >= 1.2.3
 	pytest-flake8
 	pytest-black >= 0.3.7; python_implementation != "PyPy"