From 6b1d9ab4e721b92c08f602a8d37ca1be08f88e9f Mon Sep 17 00:00:00 2001
From: Peter Korsgaard <peter@korsgaard.com>
Date: Wed, 12 Nov 2025 12:06:43 +0100
Subject: [PATCH] utils/check-package: add a check for 'default n' in Config.in
 files

Boolean Config.in symbols default to 'n', so we typically do not add such
redundant lines.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Julien Olivain <ju.o@free.fr>
(cherry picked from commit 279cbbdb646e7136c4d8b3b5b44d9b4e31ed31dd)
Signed-off-by: Thomas Perale <thomas.perale@mind.be>
---
 utils/checkpackagelib/lib_config.py      | 11 ++++++++
 utils/checkpackagelib/test_lib_config.py | 33 ++++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/utils/checkpackagelib/lib_config.py b/utils/checkpackagelib/lib_config.py
index bf975d7a3b..202baa7f1b 100644
--- a/utils/checkpackagelib/lib_config.py
+++ b/utils/checkpackagelib/lib_config.py
@@ -242,6 +242,17 @@ class Indent(_CheckFunction):
                         text]
 
 
+class NoDefaultN(_CheckFunction):
+    DEFAULTN = re.compile(r"^\tdefault n$")
+
+    def check_line(self, lineno, text):
+        text_nocomments = text.split("#")[0].rstrip()
+        if self.DEFAULTN.match(text_nocomments):
+            return ["{}:{}: boolean symbols default to 'n', so 'default n' is redundant"
+                    .format(self.filename, lineno),
+                    text]
+
+
 class RedefinedConfig(_CheckFunction):
     CONFIG = re.compile(r"^\s*(menu|)config\s+(BR2_\w+)\b")
     IF = re.compile(r"^\s*if\s+([^#]*)\b")
diff --git a/utils/checkpackagelib/test_lib_config.py b/utils/checkpackagelib/test_lib_config.py
index 474d17105e..35614ef152 100644
--- a/utils/checkpackagelib/test_lib_config.py
+++ b/utils/checkpackagelib/test_lib_config.py
@@ -387,6 +387,39 @@ def test_Indent(testname, filename, string, expected):
     assert warnings == expected
 
 
+NoDefaultN = [
+    ('good example',
+     'any',
+     'config BR2_PACKAGE_FOO\n'
+     '\tdefault y\n',
+     []),
+    ('default n',
+     'any',
+     'config BR2_PACKAGE_FOO\n'
+     '\tdefault n\n',
+     [['any:2: boolean symbols default to \'n\', so \'default n\' is redundant',
+       '\tdefault n\n']]),
+    ('default n with comment',
+     'any',
+     'config BR2_PACKAGE_FOO\n'
+     '\tdefault n # this is a comment\n',
+     [['any:2: boolean symbols default to \'n\', so \'default n\' is redundant',
+       '\tdefault n # this is a comment\n']]),
+    ('default n with trailing whitespace',
+     'any',
+     'config BR2_PACKAGE_FOO\n'
+     '\tdefault n  \t\n',
+     [['any:2: boolean symbols default to \'n\', so \'default n\' is redundant',
+       '\tdefault n  \t\n']])
+    ]
+
+
+@pytest.mark.parametrize('testname,filename,string,expected', NoDefaultN)
+def test_NoDefaultN(testname, filename, string, expected):
+    warnings = util.check_file(m.NoDefaultN, filename, string)
+    assert warnings == expected
+
+
 RedefinedConfig = [
     ('no redefinition',
      'any',