[3.14] gh-139736: Fix argparse indentation overshoot (GH-139738) (#139793)

gh-139736: Fix argparse indentation overshoot (GH-139738)
(cherry picked from commit 72e370c)

Co-authored-by: ed <[email protected]>
Co-authored-by: Savannah Ostrowski <[email protected]>

Author: 3 people

Lib/argparse.py

@@ -281,7 +281,7 @@ def add_argument(self, action):
         if action.help is not SUPPRESS:
 
             # find all invocations
-            get_invocation = self._format_action_invocation
+            get_invocation = lambda x: self._decolor(self._format_action_invocation(x))
             invocation_lengths = [len(get_invocation(action)) + self._current_indent]
             for subaction in self._iter_indented_subactions(action):
                 invocation_lengths.append(len(get_invocation(subaction)) + self._current_indent)

Lib/test/test_argparse.py

@@ -7311,11 +7311,11 @@ def custom_formatter(prog):
             {heading}usage: {reset}{prog}PROG{reset} [{short}-h{reset}] [{short}+f {label}FOO{reset}] {pos}spam{reset}
 
             {heading}positional arguments:{reset}
-                 {pos_b}spam{reset}               spam help
+                 {pos_b}spam{reset}           spam help
 
             {heading}options:{reset}
-                 {short_b}-h{reset}, {long_b}--help{reset}         show this help message and exit
-                 {short_b}+f{reset}, {long_b}++foo{reset} {label_b}FOO{reset}      foo help
+                 {short_b}-h{reset}, {long_b}--help{reset}     show this help message and exit
+                 {short_b}+f{reset}, {long_b}++foo{reset} {label_b}FOO{reset}  foo help
         '''))
 
     def test_custom_formatter_class(self):
@@ -7348,11 +7348,11 @@ def __init__(self, prog):
             {heading}usage: {reset}{prog}PROG{reset} [{short}-h{reset}] [{short}+f {label}FOO{reset}] {pos}spam{reset}
 
             {heading}positional arguments:{reset}
-                 {pos_b}spam{reset}               spam help
+                 {pos_b}spam{reset}           spam help
 
             {heading}options:{reset}
-                 {short_b}-h{reset}, {long_b}--help{reset}         show this help message and exit
-                 {short_b}+f{reset}, {long_b}++foo{reset} {label_b}FOO{reset}      foo help
+                 {short_b}-h{reset}, {long_b}--help{reset}     show this help message and exit
+                 {short_b}+f{reset}, {long_b}++foo{reset} {label_b}FOO{reset}  foo help
         '''))
 
 

Misc/NEWS.d/next/Library/2025-10-08-00-06-30.gh-issue-139736.baPeBd.rst

@@ -0,0 +1,2 @@
+Fix excessive indentation in the default :mod:`argparse`
+:class:`!HelpFormatter`. Patch by Alexander Edland.