test(config): port home include and inline header regressions

Cover the configuration regressions from PRs #2305 and #2307 against actual
`git config` output. The current configuration facade already delegates
these operations to Git, so the valid cases pass without a runtime change.

Use scripted fixtures for a real home-relative conditional include and the
complete inline-header sample. Preserve native `HOME` and `USERPROFILE`
separators so the same test exercises the Windows path case on Windows.
Check both matching and nonmatching repositories and file/stream readers.
Also check adjacent headers, an escaped quote before `]`, and rejection of
unbalanced quotes, missing/stray brackets, malformed keys and sections.

Git accepts multiple section headers on one line but omits empty sections
from `git config list`. Reflect that output and the facade's documented
empty-section limitation instead of restoring a separate Python parser.
Document the existing `GIX-12` fallback without claiming native coverage.

Validation on macOS, Git 2.54.0, Python 3.12 and GixPython 0.2.0:

- All 11 added cases passed against the unchanged runtime.
- `test/test_config.py`: 62 passed with each of the CLI and Gix backends.
- `ruff check`, `ruff format --check`, `bash -n` and `git diff --check` passed.

Windows and Linux execution was not available for this local check.

Author: codex

doc/gix-backend.md

@@ -1090,6 +1090,19 @@ former Python parser's repair of that input. General config files and
 mutations still use the CLI on both backends under GIX-12; these observations
 do not demonstrate a native Gix mismatch or eliminate any CLI calls.
 
+The October 24 ports of PRs #2305 and #2307 also compare home-relative
+`includeIf` conditions and inline section headers with Git 2.54.0. The
+conditional-include fixture uses a real repository and platform-native
+`HOME`/`USERPROFILE` paths, retaining the Windows regression case; the local
+run covered macOS only. Git accepts options after headers, quoted `]` in
+subsections, and multiple headers on one line. It rejects unbalanced quoted
+headers, missing closing brackets, stray brackets, and malformed options or
+sections. `git config list` omits empty sections, so the facade's enumeration
+also omits the original PR's empty `e` and `f` sections; their inspection is
+still unsupported. These regressions pass through the existing GIX-12 CLI
+fallback on both backends with GixPython 0.2.0. They establish no native
+compatibility bug or reduction in CLI calls.
+
 ## Other remaining operations
 
 | Operation family | Why it still uses Git |

test/test_config.py

@@ -84,6 +84,83 @@ def test_config_includes_and_repository_conditions():
         ]
 
 
+@pytest.mark.parametrize("directory, matches", [("target", True), ("other", False)])
+def test_conditional_includes_expand_home_in_git_dir_pattern(monkeypatch, directory, matches):
+    path = read_only_fixture("config.sh", "home-includes")
+    home = path / "home"
+    # Native Windows separators must reach Git's home expansion unchanged.
+    monkeypatch.setenv("HOME", str(home))
+    monkeypatch.setenv("USERPROFILE", str(home))
+    with Repo(home / directory / "repo") as repo:
+        expected = b"includeif.gitdir:~/target/.path\n./included\0"
+        if matches:
+            expected += b"values.source\nincluded\0"
+        assert (
+            repo.git.config("list", "--null", "--includes", "--file", str(path / "config"), stdout_as_string=False)
+            == expected
+        )
+        with GitConfigParser(path / "config", repo=repo) as config:
+            assert config.get('includeIf "gitdir:~/target/"', "path") == "./included"
+            assert config.has_section("values") is matches
+            if matches:
+                assert config.get_value("values", "source") == "included"
+        with GitConfigParser(path / "config", repo=repo, merge_includes=False) as config:
+            assert config.sections() == ['includeif "gitdir:~/target/"']
+
+
+@pytest.mark.parametrize("stream", [False, True])
+def test_option_after_section_header_is_read_like_git(stream):
+    path = read_only_fixture("config.sh", "inline-headers") / "config"
+    assert Git().config("list", "--null", "--file", str(path), stdout_as_string=False) == (
+        b"submodule.lib.path\nlib\0"
+        b"submodule.lib.url\nhttps://good.example/lib\0"
+        b"submodule.lib.url\nhttps://evil.example/lib\0"
+        b"a.x]y.k\nv\0b.flag\0c.k\nv ]\0d.k\nmulti  line\0g.k\nv\0"
+    )
+    source = BytesIO(path.read_bytes()) if stream else path
+    with GitConfigParser(source) as config:
+        assert config.get_value('submodule "lib"', "url") == "https://evil.example/lib"
+        assert config.get_values('submodule "lib"', "url") == ["https://good.example/lib", "https://evil.example/lib"]
+        assert config.get_value('a "x]y"', "k") == "v"
+        assert config.getboolean("b", "flag") is True
+        assert config.get_value("c", "k") == "v ]"
+        assert config.get_value("d", "k") == "multi  line"
+        assert config.get_value("g", "k") == "v"
+        # Git's enumeration omits empty sections; the facade cannot expose them.
+        for section in ("e", "f"):
+            with pytest.raises(configparser.NoSectionError):
+                config.items(section)
+        assert config.sections() == ['submodule "lib"', 'a "x]y"', "b", "c", "d", "g"]
+
+
+@pytest.mark.parametrize(
+    "case, section, key",
+    [
+        ("multiple", "third", "third.k"),
+        ("escaped-quote", 'a "x\\"]y"', 'a.x"]y.k'),
+        ("unbalanced-quote", None, None),
+        ("missing-bracket", None, None),
+        ("trailing-bracket", None, None),
+        ("invalid-option", None, None),
+        ("invalid-section", None, None),
+    ],
+)
+def test_inline_section_headers_match_git_validation(case, section, key):
+    path = read_only_fixture("config.sh", "inline-header-cases", case) / "config"
+    if section is None:
+        with pytest.raises(GitCommandError, match="bad config line") as baseline:
+            Git().config("list", "--file", str(path))
+        with GitConfigParser(path) as config, pytest.raises(configparser.ParsingError) as error:
+            config.read()
+        assert isinstance(error.value.__cause__, GitCommandError)
+        assert error.value.__cause__.status == baseline.value.status
+        return
+    assert Git().config("list", "--null", "--file", str(path)) == key + "\nv\0"
+    with GitConfigParser(path) as config:
+        assert config.sections() == [section]
+        assert config.get_value(section, "k") == "v"
+
+
 def test_config_multiple_files_and_missing_values():
     tmp_path = read_only_fixture("config.sh", "multiple")
     one, two = tmp_path / "one", tmp_path / "two"

tests/fixtures/config.sh

@@ -52,6 +52,39 @@ includes)
     gitdir=$(git -C repo rev-parse --absolute-git-dir)
     git config --file config "includeIf.gitdir:$gitdir.path" "$PWD/included"
     ;;
+home-includes)
+    git init -q home/target/repo
+    git init -q home/other/repo
+    printf '[includeIf "gitdir:~/target/"]\npath = ./included\n' > config
+    printf '[values]\nsource = included\n' > included
+    ;;
+inline-headers)
+    cat > config <<'EOF'
+[submodule "lib"]
+	path = lib
+	url = https://good.example/lib
+[submodule "lib"] url = https://evil.example/lib
+[a "x]y"] k = v # comment
+[b]flag
+[c] k = v ]
+[d] k = "multi\
+  line"
+[e] ; comment
+[f] [g] k = v
+EOF
+    ;;
+inline-header-cases)
+    case "$2" in
+        multiple) printf '[first] [second] [third] k = v\n' > config ;;
+        escaped-quote) printf '%s\n' '[a "x\"]y"] k = v' > config ;;
+        unbalanced-quote) printf '%s\n' '[a "unterminated] k = v' > config ;;
+        missing-bracket) printf '[a k = v\n' > config ;;
+        trailing-bracket) printf '[a] ]\n' > config ;;
+        invalid-option) printf '[a] invalid_key = v\n' > config ;;
+        invalid-section) printf '[a] [invalid section] k = v\n' > config ;;
+        *) exit 1 ;;
+    esac
+    ;;
 multiple)
     printf '[values]\nnumber = 1\n' > one
     printf '[values]\nnumber = 2\n' > two