Skip to content

[3.12] gh-143927: Normalize all line endings (CR, CRLF, and LF) in configparser (GH-143929) #152005

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
miss-islington wants to merge 1 commit into
base: 3.12
Choose a base branch
from
+16 −1
Open

[3.12] gh-143927: Normalize all line endings (CR, CRLF, and LF) in configparser (GH-143929) #152005

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion Lib/configparser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -907,7 +907,9 @@ def _write_section(self, fp, section_name, section_items, delimiter):
value = self._interpolation.before_write(self, section_name, key,
value)
if value is not None or not self._allow_no_value:
value = delimiter + str(value).replace('\n', '\n\t')
# Convert all possible line-endings into '\n\t'
value = (delimiter + str(value).replace('\r\n', '\n')
.replace('\r', '\n').replace('\n', '\n\t'))
else:
value = ""
fp.write("{}{}\n".format(key, value))
Expand Down
11 changes: 11 additions & 0 deletions Lib/test/test_configparser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -527,6 +527,17 @@ def test_default_case_sensitivity(self):
cf.get(self.default_section, "Foo"), "Bar",
"could not locate option, expecting case-insensitive defaults")

def test_crlf_normalization(self):
cf = self.newconfig({"key1": "a\nb","key2": "a\rb", "key3": "a\r\nb", "key4": "a\r\nb"})
buf = io.StringIO()
cf.write(buf)
cf_str = buf.getvalue()
self.assertNotIn("\r", cf_str)
self.assertNotIn("\r\n", cf_str)
self.assertEqual(cf_str.count("\n"), 10)
self.assertEqual(cf_str.count("\n\t"), 4)
self.assertTrue(cf_str.endswith("\n\n"))

def test_parse_errors(self):
cf = self.newconfig()
self.parse_error(cf, configparser.ParsingError,
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Security/2026-01-16-11-58-19.gh-issue-143927.aviFeG.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
Normalize all line endings (CR, CRLF, and LF) to LF+TAB when writing
multi-line configparser values.
Loading