Address review comments about quoted subsection validation

Review feedback: Section-name validation treated closing brackets as quoted data when an opening quote was unterminated, ended with a trailing escape, or was not a valid quoted-subsection opener. The regression matrix lacked those malformed forms.

Only enter quoted-subsection state when the opening quote follows whitespace, and reject names whose quote state remains open after scanning. Extend the writer-entry-point regression matrix with invalid-position, unterminated, and trailing-escape cases while retaining the valid quoted-bracket case.

Author: codex

git/config.py

@@ -900,15 +900,19 @@ def _assure_config_name_safe(self, name: "cp._SectionName", label: str) -> None:
         if label == "section" and isinstance(name, str):
             in_quotes = False
             escaped = False
-            for char in name:
+            for index, char in enumerate(name):
                 if escaped:
                     escaped = False
                 elif in_quotes and char == "\\":
                     escaped = True
                 elif char == '"':
+                    if not in_quotes and (index == 0 or name[index - 1] not in " \t"):
+                        raise ValueError("Git config quoted subsection names must begin after whitespace")
                     in_quotes = not in_quotes
                 elif char == "]" and not in_quotes:
                     raise ValueError("Git config section names must not contain an unquoted closing bracket")
+            if in_quotes:
+                raise ValueError("Git config section names must not contain an unterminated quote")
 
     @needs_values
     @set_dirty_and_flush_changes

test/test_config.py

@@ -197,21 +197,27 @@ def test_set_value_rejects_unsafe_section_and_option_names(self, rw_dir):
     @with_rw_directory
     def test_writer_rejects_unquoted_section_terminators(self, rw_dir):
         config_path = osp.join(rw_dir, "config")
-        bad_sections = ("user] [other", 'submodule "docs"] [other')
+        bad_sections = (
+            "user] [other",
+            'user"] [other"',
+            'submodule "docs"] [other',
+            'submodule "docs] [other',
+            'submodule "docs] [other\\',
+        )
         safe_section = 'submodule "docs]archive"'
 
         with GitConfigParser(config_path, read_only=False) as git_config:
             git_config.add_section("user")
             for bad_section in bad_sections:
-                with pytest.raises(ValueError, match="closing bracket"):
+                with pytest.raises(ValueError, match="section name"):
                     git_config.add_section(bad_section)
-                with pytest.raises(ValueError, match="closing bracket"):
+                with pytest.raises(ValueError, match="section name"):
                     git_config.set(bad_section, "name", "value")
-                with pytest.raises(ValueError, match="closing bracket"):
+                with pytest.raises(ValueError, match="section name"):
                     git_config.set_value(bad_section, "name", "value")
-                with pytest.raises(ValueError, match="closing bracket"):
+                with pytest.raises(ValueError, match="section name"):
                     git_config.add_value(bad_section, "name", "value")
-                with pytest.raises(ValueError, match="closing bracket"):
+                with pytest.raises(ValueError, match="section name"):
                     git_config.rename_section("user", bad_section)
 
             git_config.set_value("user", "name", "safe")