[3.12] gh-61011: Fix inheritance of nested mutually exclusive groups in argparse...

Previously, all nested mutually exclusive groups lost their connection
to the group containing them and were displayed as belonging directly
to the parser.

(cherry picked from commit 18c74497681e0107d7cde53e63ea42feb38f2176)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
Co-authored-by: Danica J. Sutherland <djsutherland@users.noreply.github.com>

diff --git a/Lib/argparse.py b/Lib/argparse.py
index bd5c757197fcf8c316fc443747ce547b92d378e5..2a3253453dff84955c7e64751b7462cda7c87ffa 100644 (file)
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1564,7 +1564,11 @@ class _ActionsContainer(object):
         # NOTE: if add_mutually_exclusive_group ever gains title= and
         # description= then this code will need to be expanded as above
         for group in container._mutually_exclusive_groups:
-            mutex_group = self.add_mutually_exclusive_group(
+            if group._container is container:
+                cont = self
+            else:
+                cont = title_group_map[group._container.title]
+            mutex_group = cont.add_mutually_exclusive_group(
                 required=group.required)
 
             # map the actions to their new mutex group

diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index 13d15fbf075861f4849cafa6376f79dfa2f244ac..84f8b09fb1d2a4d76fdbddd5385e7b3782064fa4 100644 (file)
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -2880,6 +2880,35 @@ class TestParentParsers(TestCase):
               -x X
         '''.format(progname, ' ' if progname else '' )))
 
+    def test_mutex_groups_parents(self):
+        parent = ErrorRaisingArgumentParser(add_help=False)
+        g = parent.add_argument_group(title='g', description='gd')
+        g.add_argument('-w')
+        g.add_argument('-x')
+        m = g.add_mutually_exclusive_group()
+        m.add_argument('-y')
+        m.add_argument('-z')
+        parser = ErrorRaisingArgumentParser(prog='PROG', parents=[parent])
+
+        self.assertRaises(ArgumentParserError, parser.parse_args,
+            ['-y', 'Y', '-z', 'Z'])
+
+        parser_help = parser.format_help()
+        self.assertEqual(parser_help, textwrap.dedent('''\
+            usage: PROG [-h] [-w W] [-x X] [-y Y | -z Z]
+
+            options:
+              -h, --help  show this help message and exit
+
+            g:
+              gd
+
+              -w W
+              -x X
+              -y Y
+              -z Z
+        '''))
+
 # ==============================
 # Mutually exclusive group tests
 # ==============================

diff --git a/Misc/ACKS b/Misc/ACKS
index b5dc32ee507689f72d4d3a2f32b609b2bbc33bbc..837ffbda18aea1012e855286bf7f695a6804ece4 100644 (file)
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1792,6 +1792,7 @@ Reuben Sumner
 Eryk Sun
 Sanjay Sundaresan
 Marek Šuppa
+Danica J. Sutherland
 Hisao Suzuki
 Kalle Svensson
 Andrew Svetlov

diff --git a/Misc/NEWS.d/next/Library/2024-10-09-21-42-43.gh-issue-61011.pQXZb1.rst b/Misc/NEWS.d/next/Library/2024-10-09-21-42-43.gh-issue-61011.pQXZb1.rst
new file mode 100644 (file)
index 0000000..20f9c0b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-09-21-42-43.gh-issue-61011.pQXZb1.rst
@@ -0,0 +1,4 @@
+Fix inheritance of nested mutually exclusive groups from parent parser in
+:class:`argparse.ArgumentParser`. Previously, all nested mutually exclusive
+groups lost their connection to the group containing them and were displayed
+as belonging directly to the parser.