From 1495ccde7b984ac9184061024f0b05112e42353d Mon Sep 17 00:00:00 2001
From: Jacob Walls <jacobtylerwalls@gmail.com>
Date: Sat, 5 Mar 2022 09:48:00 -0500
Subject: [PATCH 1/3] bpo-43292: Fix file leak in iterparse when not exhausted

---
 Lib/test/test_xml_etree.py                            |  5 +++++
 Lib/xml/etree/ElementTree.py                          | 11 ++++++-----
 Misc/ACKS                                             |  1 +
 .../Library/2022-03-05-09-43-53.bpo-25707.gTlclP.rst  |  2 ++
 4 files changed, 14 insertions(+), 5 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Library/2022-03-05-09-43-53.bpo-25707.gTlclP.rst

diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 35d901f9d08244..c82c65da85a90c 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -658,6 +658,11 @@ def test_iterparse(self):
                     'junk after document element: line 1, column 12')
             del cm, it
 
+        # Not exhausting the iterator still closes the resource (bpo-43292)
+        with warnings_helper.check_no_resource_warning(self):
+            it = iterparse(TESTFN)
+            del it
+
     def test_writefile(self):
         elem = ET.Element("tag")
         elem.text = "text"
diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index 6059e2f592d2d0..d80eaffc437e5c 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -1244,7 +1244,13 @@ def iterparse(source, events=None, parser=None):
     # Use the internal, undocumented _parser argument for now; When the
     # parser argument of iterparse is removed, this can be killed.
     pullparser = XMLPullParser(events=events, _parser=parser)
+
     def iterator():
+        nonlocal source
+        close_source = False
+        if not hasattr(source, "read"):
+            source = open(source, "rb")
+            close_source = True
         try:
             while True:
                 yield from pullparser.read_events()
@@ -1266,11 +1272,6 @@ class IterParseIterator(collections.abc.Iterator):
     it.root = None
     del iterator, IterParseIterator
 
-    close_source = False
-    if not hasattr(source, "read"):
-        source = open(source, "rb")
-        close_source = True
-
     return it
 
 
diff --git a/Misc/ACKS b/Misc/ACKS
index da2c82610d5adf..df851bb834cd4e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1879,6 +1879,7 @@ Wojtek Walczak
 Charles Waldman
 Richard Walker
 Larry Wall
+Jacob Walls
 Kevin Walzer
 Rodrigo Steinmuller Wanderley
 Dingyuan Wang
diff --git a/Misc/NEWS.d/next/Library/2022-03-05-09-43-53.bpo-25707.gTlclP.rst b/Misc/NEWS.d/next/Library/2022-03-05-09-43-53.bpo-25707.gTlclP.rst
new file mode 100644
index 00000000000000..a59f0a7657ff23
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-03-05-09-43-53.bpo-25707.gTlclP.rst
@@ -0,0 +1,2 @@
+Fixed a file leak in :func:`xml.etree.ElementTree.iterparse` when the
+iterator is not exhausted. Patch by Jacob Walls.

From b29dba75e02c47a91dc94b4ce199070491c49db5 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sun, 6 Mar 2022 16:23:19 +0200
Subject: [PATCH 2/3] Update ElementTree.py

---
 Lib/xml/etree/ElementTree.py | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index d80eaffc437e5c..5249c7ab82b84b 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -1245,13 +1245,13 @@ def iterparse(source, events=None, parser=None):
     # parser argument of iterparse is removed, this can be killed.
     pullparser = XMLPullParser(events=events, _parser=parser)
 
-    def iterator():
-        nonlocal source
+    def iterator(source):
         close_source = False
-        if not hasattr(source, "read"):
-            source = open(source, "rb")
-            close_source = True
         try:
+            if not hasattr(source, "read"):
+                source = open(source, "rb")
+                close_source = True
+            yield None
             while True:
                 yield from pullparser.read_events()
                 # load event buffer
@@ -1267,11 +1267,12 @@ def iterator():
                 source.close()
 
     class IterParseIterator(collections.abc.Iterator):
-        __next__ = iterator().__next__
+        __next__ = iterator(source).__next__
     it = IterParseIterator()
     it.root = None
     del iterator, IterParseIterator
 
+    next(it)
     return it
 
 

From f532022dc684dcb768afc1cb3d6717c96aac1ed9 Mon Sep 17 00:00:00 2001
From: Serhiy Storchaka <storchaka@gmail.com>
Date: Sun, 6 Mar 2022 16:23:41 +0200
Subject: [PATCH 3/3] Update Lib/test/test_xml_etree.py

---
 Lib/test/test_xml_etree.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index c82c65da85a90c..d2bdc4f7f04445 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -663,6 +663,9 @@ def test_iterparse(self):
             it = iterparse(TESTFN)
             del it
 
+        with self.assertRaises(FileNotFoundError):
+            iterparse("nonexistent")
+
     def test_writefile(self):
         elem = ET.Element("tag")
         elem.text = "text"