From 12efd8a72bdafae62601728799636811a45e865c Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Sun, 12 Apr 2026 19:28:26 +0800
Subject: [PATCH 1/7] gh-148428: Fix file handle leak in pulldom.parse()

When pulldom.parse() is called with a filename, the opened file handle
is never closed. Add close(), context manager support, and __del__ with
ResourceWarning to DOMEventStream. Update clear() to close owned streams.
---
 Doc/library/xml.dom.pulldom.rst               | 12 +++++
 Lib/test/test_pulldom.py                      | 47 +++++++++++++++++--
 Lib/xml/dom/pulldom.py                        | 31 +++++++++++-
 ...-04-12-11-14-40.gh-issue-148428.kP9qWx.rst |  4 ++
 4 files changed, 88 insertions(+), 6 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst

diff --git a/Doc/library/xml.dom.pulldom.rst b/Doc/library/xml.dom.pulldom.rst
index 52340ffe92eb857..1732f2ce2c044e3 100644
--- a/Doc/library/xml.dom.pulldom.rst
+++ b/Doc/library/xml.dom.pulldom.rst
@@ -114,6 +114,10 @@ DOMEventStream Objects
    .. versionchanged:: 3.11
       Support for :meth:`~object.__getitem__` method has been removed.
 
+   .. versionchanged:: next
+      :class:`DOMEventStream` now supports the :term:`context manager`
+      protocol. File handles opened by :func:`parse` are closed on exit.
+
    .. method:: getEvent()
 
       Return a tuple containing *event* and the current *node* as
@@ -141,3 +145,11 @@ DOMEventStream Objects
                   print(node.toxml())
 
    .. method:: DOMEventStream.reset()
+
+   .. method:: DOMEventStream.close()
+
+      Close the underlying stream if it was opened by :func:`parse`.
+      Has no effect if the stream was provided by the caller or is already
+      closed. It is safe to call this method more than once.
+
+      .. versionadded:: next
diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index 3c8ed251acaa4d8..60ad70182bbe03b 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -6,6 +6,7 @@
 from xml.sax.handler import feature_external_ges
 from xml.dom import pulldom
 
+from test import support
 from test.support import findfile
 
 
@@ -31,15 +32,53 @@ def test_parse(self):
         # semantics are tested using parseString with a more focused XML
         # fragment.
 
-        # Test with a filename:
-        handler = pulldom.parse(tstfile)
-        self.addCleanup(handler.stream.close)
-        list(handler)
+        # Test with a filename (context manager):
+        with pulldom.parse(tstfile) as handler:
+            list(handler)
 
         # Test with a file object:
         with open(tstfile, "rb") as fin:
             list(pulldom.parse(fin))
 
+    def test_context_manager_closes_file(self):
+        # gh-148428: context manager should close owned stream
+        with pulldom.parse(tstfile) as events:
+            stream = events.stream
+            for event, node in events:
+                pass
+        self.assertTrue(stream.closed)
+
+    def test_context_manager_does_not_close_user_stream(self):
+        # gh-148428: context manager must not close user-provided streams
+        with open(tstfile, 'rb') as f:
+            events = pulldom.DOMEventStream(f, xml.sax.make_parser(), 16384)
+            for event, node in events:
+                pass
+            events.close()
+            self.assertFalse(f.closed)
+
+    def test_close_is_idempotent(self):
+        # gh-148428: calling close() multiple times should be safe
+        events = pulldom.parse(tstfile)
+        stream = events.stream
+        events.close()
+        self.assertTrue(stream.closed)
+        events.close()  # should not raise
+
+    def test_clear_closes_owned_stream(self):
+        # gh-148428: clear() should close the stream when parse() opened it
+        events = pulldom.parse(tstfile)
+        stream = events.stream
+        events.clear()
+        self.assertTrue(stream.closed)
+
+    def test_resource_warning_on_del(self):
+        # gh-148428: unclosed DOMEventStream should emit ResourceWarning
+        events = pulldom.parse(tstfile)
+        with self.assertWarns(ResourceWarning):
+            del events
+            support.gc_collect()
+
     def test_parse_semantics(self):
         """Test DOMEventStream parsing semantics."""
 
diff --git a/Lib/xml/dom/pulldom.py b/Lib/xml/dom/pulldom.py
index 913141cd7ef3ceb..f5626b5365ea1e2 100644
--- a/Lib/xml/dom/pulldom.py
+++ b/Lib/xml/dom/pulldom.py
@@ -1,3 +1,4 @@
+import warnings
 import xml.sax
 import xml.sax.handler
 
@@ -202,10 +203,11 @@ def fatalError(self, exception):
         raise exception
 
 class DOMEventStream:
-    def __init__(self, stream, parser, bufsize):
+    def __init__(self, stream, parser, bufsize, _owns_stream=False):
         self.stream = stream
         self.parser = parser
         self.bufsize = bufsize
+        self._owns_stream = _owns_stream
         if not hasattr(self.parser, 'feed'):
             self.getEvent = self._slurp
         self.reset()
@@ -225,6 +227,28 @@ def __next__(self):
     def __iter__(self):
         return self
 
+    def close(self):
+        """Close the stream if it was opened by parse()."""
+        if self._owns_stream and self.stream is not None:
+            self.stream.close()
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
+    def __del__(self, _warn=warnings.warn):
+        if self._owns_stream and self.stream is not None:
+            try:
+                if not self.stream.closed:
+                    _warn(
+                        f"unclosed {self!r}",
+                        ResourceWarning,
+                        source=self)
+            finally:
+                self.stream.close()
+
     def expandNode(self, node):
         event = self.getEvent()
         parents = [node]
@@ -275,6 +299,7 @@ def _emit(self):
 
     def clear(self):
         """clear(): Explicitly release parsing objects"""
+        self.close()
         self.pulldom.clear()
         del self.pulldom
         self.parser = None
@@ -320,11 +345,13 @@ def parse(stream_or_string, parser=None, bufsize=None):
         bufsize = default_bufsize
     if isinstance(stream_or_string, str):
         stream = open(stream_or_string, 'rb')
+        owns_stream = True
     else:
         stream = stream_or_string
+        owns_stream = False
     if not parser:
         parser = xml.sax.make_parser()
-    return DOMEventStream(stream, parser, bufsize)
+    return DOMEventStream(stream, parser, bufsize, _owns_stream=owns_stream)
 
 def parseString(string, parser=None):
     from io import StringIO
diff --git a/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst b/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst
new file mode 100644
index 000000000000000..f5befbd514a2867
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst
@@ -0,0 +1,4 @@
+:class:`xml.dom.pulldom.DOMEventStream` now supports the :term:`context
+manager` protocol and has a :meth:`~xml.dom.pulldom.DOMEventStream.close`
+method. File handles opened by :func:`xml.dom.pulldom.parse` are now
+properly closed, fixing a resource leak.

From 282886b1fd490d351de2d4b201d91e1a2205f052 Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Sun, 12 Apr 2026 20:59:17 +0800
Subject: [PATCH 2/7] gh-148428: Revert off-topic change to test_parse

Keep the existing test_parse unchanged; context manager behavior is
covered by the new dedicated tests.
---
 Lib/test/test_pulldom.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index 60ad70182bbe03b..2a53dd1d87e11f9 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -32,9 +32,10 @@ def test_parse(self):
         # semantics are tested using parseString with a more focused XML
         # fragment.
 
-        # Test with a filename (context manager):
-        with pulldom.parse(tstfile) as handler:
-            list(handler)
+        # Test with a filename:
+        handler = pulldom.parse(tstfile)
+        self.addCleanup(handler.stream.close)
+        list(handler)
 
         # Test with a file object:
         with open(tstfile, "rb") as fin:

From 57840f65bd94c5156695e8b98dda3ac69331bb66 Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Sun, 12 Apr 2026 21:01:48 +0800
Subject: [PATCH 3/7] gh-148428: Remove redundant test and off-topic change

Remove test_context_manager_closes_file (covered by test_close_is_idempotent)
and revert the unrelated modification to test_parse.
---
 Lib/test/test_pulldom.py | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index 2a53dd1d87e11f9..abe7113ca7fbcca 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -41,14 +41,6 @@ def test_parse(self):
         with open(tstfile, "rb") as fin:
             list(pulldom.parse(fin))
 
-    def test_context_manager_closes_file(self):
-        # gh-148428: context manager should close owned stream
-        with pulldom.parse(tstfile) as events:
-            stream = events.stream
-            for event, node in events:
-                pass
-        self.assertTrue(stream.closed)
-
     def test_context_manager_does_not_close_user_stream(self):
         # gh-148428: context manager must not close user-provided streams
         with open(tstfile, 'rb') as f:

From baaf87fb48a450656952677ad4548083aa66933b Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Sun, 12 Apr 2026 21:38:34 +0800
Subject: [PATCH 4/7] gh-148428: Fix test_parse ResourceWarning from __del__

Use handler.close() instead of handler.stream.close() in addCleanup
so the DOMEventStream is properly closed before GC triggers __del__.
---
 Lib/test/test_pulldom.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index abe7113ca7fbcca..594ce1dd8af32c4 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -34,7 +34,7 @@ def test_parse(self):
 
         # Test with a filename:
         handler = pulldom.parse(tstfile)
-        self.addCleanup(handler.stream.close)
+        self.addCleanup(handler.close)
         list(handler)
 
         # Test with a file object:

From 2c2c5d5872db7ea3db23df4523ecbb085601ac48 Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Tue, 1 Sep 2026 21:45:22 +0800
Subject: [PATCH 5/7] gh-148428: Address review: remove __del__ and simplify
 tests

The file object opened by parse() already emits its own ResourceWarning
when collected unclosed, so DOMEventStream.__del__ is not needed.

Rewrite test_context_manager_does_not_close_user_stream to actually use
the context manager and pulldom.parse(), and drop comments that repeat
the test names.
---
 Lib/test/test_pulldom.py | 17 ++---------------
 Lib/xml/dom/pulldom.py   | 12 ------------
 2 files changed, 2 insertions(+), 27 deletions(-)

diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index 594ce1dd8af32c4..9fc4a8ebb07a56a 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -6,7 +6,6 @@
 from xml.sax.handler import feature_external_ges
 from xml.dom import pulldom
 
-from test import support
 from test.support import findfile
 
 
@@ -42,16 +41,12 @@ def test_parse(self):
             list(pulldom.parse(fin))
 
     def test_context_manager_does_not_close_user_stream(self):
-        # gh-148428: context manager must not close user-provided streams
         with open(tstfile, 'rb') as f:
-            events = pulldom.DOMEventStream(f, xml.sax.make_parser(), 16384)
-            for event, node in events:
-                pass
-            events.close()
+            with pulldom.parse(f) as events:
+                list(events)
             self.assertFalse(f.closed)
 
     def test_close_is_idempotent(self):
-        # gh-148428: calling close() multiple times should be safe
         events = pulldom.parse(tstfile)
         stream = events.stream
         events.close()
@@ -59,19 +54,11 @@ def test_close_is_idempotent(self):
         events.close()  # should not raise
 
     def test_clear_closes_owned_stream(self):
-        # gh-148428: clear() should close the stream when parse() opened it
         events = pulldom.parse(tstfile)
         stream = events.stream
         events.clear()
         self.assertTrue(stream.closed)
 
-    def test_resource_warning_on_del(self):
-        # gh-148428: unclosed DOMEventStream should emit ResourceWarning
-        events = pulldom.parse(tstfile)
-        with self.assertWarns(ResourceWarning):
-            del events
-            support.gc_collect()
-
     def test_parse_semantics(self):
         """Test DOMEventStream parsing semantics."""
 
diff --git a/Lib/xml/dom/pulldom.py b/Lib/xml/dom/pulldom.py
index f5626b5365ea1e2..00ddf9eecfbb3e9 100644
--- a/Lib/xml/dom/pulldom.py
+++ b/Lib/xml/dom/pulldom.py
@@ -1,4 +1,3 @@
-import warnings
 import xml.sax
 import xml.sax.handler
 
@@ -238,17 +237,6 @@ def __enter__(self):
     def __exit__(self, *args):
         self.close()
 
-    def __del__(self, _warn=warnings.warn):
-        if self._owns_stream and self.stream is not None:
-            try:
-                if not self.stream.closed:
-                    _warn(
-                        f"unclosed {self!r}",
-                        ResourceWarning,
-                        source=self)
-            finally:
-                self.stream.close()
-
     def expandNode(self, node):
         event = self.getEvent()
         parents = [node]

From 15c3f4c6f6c7a59651f6b20c9a2c6de68d0ab041 Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Tue, 1 Sep 2026 21:56:38 +0800
Subject: [PATCH 6/7] gh-148428: Make clear() the single cleanup method

Per review: close() is removed, clear() now closes the stream when it
was opened by parse() (and is safe to call more than once), and the
context manager calls clear() on exit.

Since minidom's _do_pulldom_parse() already calls clear(), this also
fixes the file handle leak in xml.dom.minidom.parse() with a custom
parser.

Also update the leaking example in the documentation to use the with
statement.
---
 Doc/library/xml.dom.pulldom.rst               | 27 ++++++++++---------
 Lib/test/test_pulldom.py                      | 16 +++++------
 Lib/xml/dom/pulldom.py                        | 15 +++++------
 ...-04-12-11-14-40.gh-issue-148428.kP9qWx.rst |  9 ++++---
 4 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/Doc/library/xml.dom.pulldom.rst b/Doc/library/xml.dom.pulldom.rst
index 1732f2ce2c044e3..c70d20b94c6e6db 100644
--- a/Doc/library/xml.dom.pulldom.rst
+++ b/Doc/library/xml.dom.pulldom.rst
@@ -41,12 +41,12 @@ Example::
 
    from xml.dom import pulldom
 
-   doc = pulldom.parse('sales_items.xml')
-   for event, node in doc:
-       if event == pulldom.START_ELEMENT and node.tagName == 'item':
-           if int(node.getAttribute('price')) > 50:
-               doc.expandNode(node)
-               print(node.toxml())
+   with pulldom.parse('sales_items.xml') as doc:
+       for event, node in doc:
+           if event == pulldom.START_ELEMENT and node.tagName == 'item':
+               if int(node.getAttribute('price')) > 50:
+                   doc.expandNode(node)
+                   print(node.toxml())
 
 ``event`` is a constant and can be one of:
 
@@ -115,8 +115,9 @@ DOMEventStream Objects
       Support for :meth:`~object.__getitem__` method has been removed.
 
    .. versionchanged:: next
-      :class:`DOMEventStream` now supports the :term:`context manager`
-      protocol. File handles opened by :func:`parse` are closed on exit.
+      :class:`DOMEventStream` can now be used as a :term:`context manager`.
+      On exit, :meth:`~DOMEventStream.clear` is called, closing file
+      handles opened by :func:`parse`.
 
    .. method:: getEvent()
 
@@ -146,10 +147,12 @@ DOMEventStream Objects
 
    .. method:: DOMEventStream.reset()
 
-   .. method:: DOMEventStream.close()
+   .. method:: DOMEventStream.clear()
 
-      Close the underlying stream if it was opened by :func:`parse`.
-      Has no effect if the stream was provided by the caller or is already
+      Release the parsing objects and close the underlying stream if it
+      was opened by :func:`parse`. Streams provided by the caller are not
       closed. It is safe to call this method more than once.
 
-      .. versionadded:: next
+      .. versionchanged:: next
+         This method now closes the underlying stream if it was opened
+         by :func:`parse`.
diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index 9fc4a8ebb07a56a..f43b0885bffbc1e 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -33,31 +33,31 @@ def test_parse(self):
 
         # Test with a filename:
         handler = pulldom.parse(tstfile)
-        self.addCleanup(handler.close)
+        self.addCleanup(handler.clear)
         list(handler)
 
         # Test with a file object:
         with open(tstfile, "rb") as fin:
             list(pulldom.parse(fin))
 
+    def test_context_manager_closes_owned_stream(self):
+        with pulldom.parse(tstfile) as events:
+            stream = events.stream
+            list(events)
+        self.assertTrue(stream.closed)
+
     def test_context_manager_does_not_close_user_stream(self):
         with open(tstfile, 'rb') as f:
             with pulldom.parse(f) as events:
                 list(events)
             self.assertFalse(f.closed)
 
-    def test_close_is_idempotent(self):
-        events = pulldom.parse(tstfile)
-        stream = events.stream
-        events.close()
-        self.assertTrue(stream.closed)
-        events.close()  # should not raise
-
     def test_clear_closes_owned_stream(self):
         events = pulldom.parse(tstfile)
         stream = events.stream
         events.clear()
         self.assertTrue(stream.closed)
+        events.clear()  # should not raise
 
     def test_parse_semantics(self):
         """Test DOMEventStream parsing semantics."""
diff --git a/Lib/xml/dom/pulldom.py b/Lib/xml/dom/pulldom.py
index 00ddf9eecfbb3e9..be82369a9ef7258 100644
--- a/Lib/xml/dom/pulldom.py
+++ b/Lib/xml/dom/pulldom.py
@@ -226,16 +226,11 @@ def __next__(self):
     def __iter__(self):
         return self
 
-    def close(self):
-        """Close the stream if it was opened by parse()."""
-        if self._owns_stream and self.stream is not None:
-            self.stream.close()
-
     def __enter__(self):
         return self
 
     def __exit__(self, *args):
-        self.close()
+        self.clear()
 
     def expandNode(self, node):
         event = self.getEvent()
@@ -287,9 +282,11 @@ def _emit(self):
 
     def clear(self):
         """clear(): Explicitly release parsing objects"""
-        self.close()
-        self.pulldom.clear()
-        del self.pulldom
+        if self._owns_stream and self.stream is not None:
+            self.stream.close()
+        if self.pulldom is not None:
+            self.pulldom.clear()
+        self.pulldom = None
         self.parser = None
         self.stream = None
 
diff --git a/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst b/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst
index f5befbd514a2867..301b33596c419f0 100644
--- a/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst
+++ b/Misc/NEWS.d/next/Library/2026-04-12-11-14-40.gh-issue-148428.kP9qWx.rst
@@ -1,4 +1,5 @@
-:class:`xml.dom.pulldom.DOMEventStream` now supports the :term:`context
-manager` protocol and has a :meth:`~xml.dom.pulldom.DOMEventStream.close`
-method. File handles opened by :func:`xml.dom.pulldom.parse` are now
-properly closed, fixing a resource leak.
+:class:`xml.dom.pulldom.DOMEventStream` can now be used as a :term:`context
+manager`, and its :meth:`~xml.dom.pulldom.DOMEventStream.clear` method now
+closes the file opened by :func:`xml.dom.pulldom.parse`, fixing a resource
+leak. This also fixes the file handle leak in :func:`xml.dom.minidom.parse`
+when a custom *parser* is used.

From 9984c8f153a7ec040037f5a6286f304d52190afa Mon Sep 17 00:00:00 2001
From: WYSIATI <chester.lee.cold@gmail.com>
Date: Wed, 2 Sep 2026 09:11:56 +0800
Subject: [PATCH 7/7] gh-148428: Address review: docstring, doc markup,
 user-stream clear() test

---
 Doc/library/xml.dom.pulldom.rst | 10 ++++++----
 Lib/test/test_pulldom.py        |  7 +++++++
 Lib/xml/dom/pulldom.py          |  5 ++++-
 3 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/Doc/library/xml.dom.pulldom.rst b/Doc/library/xml.dom.pulldom.rst
index c70d20b94c6e6db..e886e08f7b3400d 100644
--- a/Doc/library/xml.dom.pulldom.rst
+++ b/Doc/library/xml.dom.pulldom.rst
@@ -147,11 +147,13 @@ DOMEventStream Objects
 
    .. method:: DOMEventStream.reset()
 
-   .. method:: DOMEventStream.clear()
+   .. method:: clear()
 
-      Release the parsing objects and close the underlying stream if it
-      was opened by :func:`parse`. Streams provided by the caller are not
-      closed. It is safe to call this method more than once.
+      Release references to the parser, the stream and the DOM builder,
+      and close the stream if it was opened by :func:`parse`. Streams
+      provided by the caller are not closed. It is safe to call this
+      method more than once. The event stream cannot be used after
+      calling this method.
 
       .. versionchanged:: next
          This method now closes the underlying stream if it was opened
diff --git a/Lib/test/test_pulldom.py b/Lib/test/test_pulldom.py
index f43b0885bffbc1e..7261b5a856919df 100644
--- a/Lib/test/test_pulldom.py
+++ b/Lib/test/test_pulldom.py
@@ -59,6 +59,13 @@ def test_clear_closes_owned_stream(self):
         self.assertTrue(stream.closed)
         events.clear()  # should not raise
 
+    def test_clear_does_not_close_user_stream(self):
+        with open(tstfile, 'rb') as f:
+            events = pulldom.parse(f)
+            list(events)
+            events.clear()
+            self.assertFalse(f.closed)
+
     def test_parse_semantics(self):
         """Test DOMEventStream parsing semantics."""
 
diff --git a/Lib/xml/dom/pulldom.py b/Lib/xml/dom/pulldom.py
index be82369a9ef7258..91aa97546658f98 100644
--- a/Lib/xml/dom/pulldom.py
+++ b/Lib/xml/dom/pulldom.py
@@ -281,7 +281,10 @@ def _emit(self):
         return rc
 
     def clear(self):
-        """clear(): Explicitly release parsing objects"""
+        """Release the parsing objects.
+
+        The stream is closed if it was opened by parse().
+        """
         if self._owns_stream and self.stream is not None:
             self.stream.close()
         if self.pulldom is not None: