Work around incomplete implementation of importlib.resources.files on…

… Python 3.9

product/runtime/src/main/python/java/android/importer.py

@@ -84,6 +84,12 @@ def hook(path):
         # get_importer returns.
         site.addsitedir(finder.extract_root)
 
+    if sys.version_info[:2] == (3, 9):
+        from importlib import _common
+        global fallback_resources_original
+        fallback_resources_original = _common.fallback_resources
+        _common.fallback_resources = fallback_resources_39
+
     global spec_from_file_location_original
     spec_from_file_location_original = util.spec_from_file_location
     util.spec_from_file_location = spec_from_file_location_override
@@ -96,6 +102,14 @@ def hook(path):
     machinery.ExtensionFileLoader.create_module = extension_create_module_override
 
 
+# Python 3.9 only supports importlib.resources.files for the standard importers.
+def fallback_resources_39(spec):
+    if isinstance(spec.loader, AssetLoader):
+        return spec.loader.get_resource_reader(spec.name).files()
+    else:
+        return fallback_resources_original(spec)
+
+
 def spec_from_file_location_override(name, location=None, *args, loader=None, **kwargs):
     if location and not loader:
         head, tail = split(location)

product/runtime/src/test/python/chaquopy/test/android/test_import.py

@@ -19,6 +19,7 @@
 from unittest import skipIf
 import types
 from warnings import catch_warnings, filterwarnings
+import zipfile
 
 from java.android import importer
 
@@ -953,6 +954,20 @@ def test_resources_new(self):
             "// MurmurHash2 was written by Austin Appleby")
         self.check_resource_new(REQS_ABI_ZIP, pkg, "mrmr.so", b"\x7fELF")
 
+        # Stdlib
+        pkg_path = resources.files("email")
+        self.assertIsInstance(pkg_path, zipfile.Path)
+        self.assertTrue(pkg_path.is_dir())
+
+        children = [child.name for child in pkg_path.iterdir()]
+        self.assertIn("mime", children)
+        self.assertTrue((pkg_path / "mime").is_dir())
+
+        self.assertIn("parser.pyc", children)
+        path = pkg_path / "parser.pyc"
+        self.assertFalse(path.is_dir())
+        self.assertPredicate(path.read_bytes().startswith, MAGIC_NUMBER)
+
     def check_resource_dir(self, path, children):
         self.assertTrue(path.exists())
         self.assertTrue(path.is_dir())