From 86d6dda49580aec567c3d4f7a7594d72db05800d Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sat, 19 Sep 2026 18:43:24 +0300
Subject: [PATCH] gh-135683: Honor raiseExceptions when opening the file fails
 in FileHandler (GH-154542)

FileHandler and WatchedFileHandler opened the file outside the try block
that reports errors via handleError(), so an error while opening the file
was raised instead of being handled, ignoring raiseExceptions.
(cherry picked from commit e8ac9c4369b383d38806245bf5789689af1e19cd)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 Lib/logging/__init__.py                       |  7 +++-
 Lib/logging/handlers.py                       |  9 ++++-
 Lib/test/test_logging.py                      | 40 +++++++++++++++++++
 ...-07-23-14-13-39.gh-issue-135683.droBu7.rst |  3 ++
 4 files changed, 56 insertions(+), 3 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-07-23-14-13-39.gh-issue-135683.droBu7.rst

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 6e7606269fb7133..d03d8d2e57341c5 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -1260,7 +1260,12 @@ def emit(self, record):
         """
         if self.stream is None:
             if self.mode != 'w' or not self._closed:
-                self.stream = self._open()
+                # Report an error while opening the file, like emit errors.
+                try:
+                    self.stream = self._open()
+                except Exception:
+                    self.handleError(record)
+                    return
         if self.stream:
             StreamHandler.emit(self, record)
 
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index 4a07258f8d6d07e..ac3b7b7df3f4fd6 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -540,8 +540,13 @@ def emit(self, record):
         If underlying file has changed, reopen the file before emitting the
         record to it.
         """
-        self.reopenIfNeeded()
-        logging.FileHandler.emit(self, record)
+        # Report an error while reopening the file, like emit errors.
+        try:
+            self.reopenIfNeeded()
+        except Exception:
+            self.handleError(record)
+        else:
+            logging.FileHandler.emit(self, record)
 
 
 class SocketHandler(logging.Handler):
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 9c626ace7f55d5a..640718d5f674740 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -6343,6 +6343,46 @@ def test_emit_after_closing_in_write_mode(self):
         with open(self.fn) as fp:
             self.assertEqual(fp.read().strip(), '1')
 
+    def _check_open_error(self, h):
+        # gh-135683: an error while opening the file in emit() respects
+        # raiseExceptions, like an error during the actual write.
+        r = logging.makeLogRecord({})
+        old_raise = logging.raiseExceptions
+        self.addCleanup(setattr, logging, 'raiseExceptions', old_raise)
+
+        logging.raiseExceptions = True
+        with support.captured_stderr() as stderr:
+            h.handle(r)
+        self.assertIn('\nFileNotFoundError:', stderr.getvalue())
+
+        logging.raiseExceptions = False
+        with support.captured_stderr() as stderr:
+            h.handle(r)
+        self.assertEqual('', stderr.getvalue())
+
+    def test_emit_open_error(self):
+        # FileHandler with delay: the failing open happens in emit().
+        d = tempfile.mkdtemp()
+        self.addCleanup(os_helper.rmtree, d)
+        h = logging.FileHandler(os.path.join(d, 'missing', 'a.log'),
+                                encoding='utf-8', delay=True)
+        self.addCleanup(h.close)
+        self._check_open_error(h)
+
+    @unittest.skipIf(os.name == 'nt',
+                     'WatchedFileHandler not appropriate for Windows.')
+    def test_emit_reopen_error(self):
+        # WatchedFileHandler: reopenIfNeeded() fails after the dir is removed.
+        d = tempfile.mkdtemp()
+        self.addCleanup(os_helper.rmtree, d)
+        subdir = os.path.join(d, 'sub')
+        os.mkdir(subdir)
+        h = logging.handlers.WatchedFileHandler(
+            os.path.join(subdir, 'b.log'), encoding='utf-8')
+        self.addCleanup(h.close)
+        os_helper.rmtree(subdir)
+        self._check_open_error(h)
+
 class RotatingFileHandlerTest(BaseFileTest):
     def test_should_not_rollover(self):
         # If file is empty rollover never occurs
diff --git a/Misc/NEWS.d/next/Library/2026-07-23-14-13-39.gh-issue-135683.droBu7.rst b/Misc/NEWS.d/next/Library/2026-07-23-14-13-39.gh-issue-135683.droBu7.rst
new file mode 100644
index 000000000000000..532ae22d017a565
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-07-23-14-13-39.gh-issue-135683.droBu7.rst
@@ -0,0 +1,3 @@
+:class:`logging.FileHandler` and :class:`logging.handlers.WatchedFileHandler`
+now honor :data:`logging.raiseExceptions` for errors that occur while opening
+the file, like for other errors during logging.