[3.13] GH-87041: Fix incorrect indentation in argparse help (GH-124230) (#124373)

GH-87041: Fix incorrect indentation in argparse help (GH-124230)

In case of usage a long command along with max_help_position more than
the length of the command, the command's help was incorrectly started
on the new line.

(cherry picked from commit 7ee99217345af3010bf05b1f5241c661a5e0ea9b)

Co-authored-by: Savannah Ostrowski <savannahostrowski@gmail.com>
Co-authored-by: Pavel Ditenbir <pavel.ditenbir@gmail.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index b1f72a3..753a8da 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -4981,6 +4981,46 @@ class TestHelpMetavarTypeFormatter(HelpTestCase):
     version = ''
 
 
+class TestHelpUsageLongSubparserCommand(TestCase):
+    """Test that subparser commands are formatted correctly in help"""
+    maxDiff = None
+
+    def test_parent_help(self):
+        def custom_formatter(prog):
+            return argparse.RawTextHelpFormatter(prog, max_help_position=50)
+
+        parent_parser = argparse.ArgumentParser(
+                prog='PROG',
+                formatter_class=custom_formatter
+        )
+
+        cmd_subparsers = parent_parser.add_subparsers(title="commands",
+                                                      metavar='CMD',
+                                                      help='command to use')
+        cmd_subparsers.add_parser("add",
+                                  help="add something")
+
+        cmd_subparsers.add_parser("remove",
+                                  help="remove something")
+
+        cmd_subparsers.add_parser("a-very-long-command",
+                                  help="command that does something")
+
+        parser_help = parent_parser.format_help()
+        self.assertEqual(parser_help, textwrap.dedent('''\
+            usage: PROG [-h] CMD ...
+
+            options:
+              -h, --help             show this help message and exit
+
+            commands:
+              CMD                    command to use
+                add                  add something
+                remove               remove something
+                a-very-long-command  command that does something
+        '''))
+
+
 # =====================================
 # Optional/Positional constructor tests
 # =====================================