From ee47670e8b8648b14fd4cb64a9d47d6ed3c5b6b7 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@python.org>
Date: Mon, 30 Jun 2025 16:33:01 +0200
Subject: [PATCH] gh-85702: Catch PermissionError in zoneinfo.load_tzdata()
 (#136117)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
---
 Lib/zoneinfo/_common.py                                   | 8 ++++++--
 .../Library/2025-06-30-11-12-24.gh-issue-85702.0Lrbwu.rst | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2025-06-30-11-12-24.gh-issue-85702.0Lrbwu.rst

diff --git a/Lib/zoneinfo/_common.py b/Lib/zoneinfo/_common.py
index 6e05abc3239..03cc42149f9 100644
--- a/Lib/zoneinfo/_common.py
+++ b/Lib/zoneinfo/_common.py
@@ -9,9 +9,13 @@ def load_tzdata(key):
     resource_name = components[-1]
 
     try:
-        return resources.files(package_name).joinpath(resource_name).open("rb")
+        path = resources.files(package_name).joinpath(resource_name)
+        # gh-85702: Prevent PermissionError on Windows
+        if path.is_dir():
+            raise IsADirectoryError
+        return path.open("rb")
     except (ImportError, FileNotFoundError, UnicodeEncodeError, IsADirectoryError):
-        # There are three types of exception that can be raised that all amount
+        # There are four types of exception that can be raised that all amount
         # to "we cannot find this key":
         #
         # ImportError: If package_name doesn't exist (e.g. if tzdata is not
diff --git a/Misc/NEWS.d/next/Library/2025-06-30-11-12-24.gh-issue-85702.0Lrbwu.rst b/Misc/NEWS.d/next/Library/2025-06-30-11-12-24.gh-issue-85702.0Lrbwu.rst
new file mode 100644
index 00000000000..fc13eb1d9e0
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-06-30-11-12-24.gh-issue-85702.0Lrbwu.rst
@@ -0,0 +1,3 @@
+If ``zoneinfo._common.load_tzdata`` is given a package without a resource a
+:exc:`zoneinfo.ZoneInfoNotFoundError` is raised rather than a :exc:`PermissionError`.
+Patch by Victor Stinner.