row 283 (#1788): webby-0236 E5: the git round-trip test drops GIT_DIR, GIT_WORK_TREE, GIT_COMMON_DIR and GIT_INDEX_FILE and reads no global or system config (repo convention); BUILD.md records E5. Untested

agents/honker/work/queue-283/BUILD.md

@@ -177,3 +177,12 @@ M6c now replaces the whole end check (this supersedes the earlier M6c row):
 |---|---|---|---|---|
 | M6c | src/mapping.mjs | `if (value.trim() !== value \|\| IDENT_CRUD_END.test(value))` | `if (false)` | mapping.test "editor is optional" (end cases) |
 | M6d | src/mapping.mjs | `if (value.trim() !== value \|\| IDENT_CRUD_END.test(value))` | `if (value.trim() !== value)` | mapping.test "editor is optional" (`,` `:` `;` `"` `'` `\` cases) |
+
+## 2026-10-23 E5 (webby-0236, not blocking), fixed
+
+The round-trip test stripped only GIT_AUTHOR_* and GIT_COMMITTER_*. With GIT_DIR, GIT_WORK_TREE or
+GIT_INDEX_FILE set (inside a hook, say), GIT_DIR beats `-C root` and the commit would land in the
+outer repo, and the test read global and system config. It now deletes GIT_DIR, GIT_WORK_TREE,
+GIT_COMMON_DIR and GIT_INDEX_FILE (as queue/tests/helpers.mjs gitEnv does) and sets
+GIT_CONFIG_GLOBAL=/dev/null and GIT_CONFIG_NOSYSTEM=1 (as ledger.test.mjs does). The `-c user.*`
+ident still applies. Test only; no mutant changes.

packages/library/tests/mapping.test.mjs

@@ -145,8 +145,11 @@ test('C2-01d: an accepted editor round-trips through a real git commit unchanged
   const editor = mapping(e => ({ ...e, editor: { name: 'Doe, Jane Q.', email: '[email protected].' } })).editor;
   const root = mkdtempSync(join(tmpdir(), 'library-ident-'));
   t.after(() => rmSync(root, { recursive: true, force: true }));
-  // An ident in the environment would win over -c, so the commit runs without one.
+  // An ident in the environment would win over -c, so the commit runs without one. GIT_DIR and its
+  // family would beat -C (inside a hook, say), and git reads no global or system config (webby-0236 E5).
   const env = Object.fromEntries(Object.entries(process.env).filter(([k]) => !/^GIT_(AUTHOR|COMMITTER)_/.test(k)));
+  for (const k of ['GIT_DIR', 'GIT_WORK_TREE', 'GIT_COMMON_DIR', 'GIT_INDEX_FILE']) delete env[k];
+  Object.assign(env, { GIT_CONFIG_GLOBAL: '/dev/null', GIT_CONFIG_NOSYSTEM: '1' });
   const git = (...args) => execFileSync('git', ['-c', `user.name=${editor.name}`, '-c', `user.email=${editor.email}`,
     '-c', 'commit.gpgsign=false', '-c', 'core.hooksPath=/dev/null', '-C', root, ...args], { encoding: 'utf8', env });
   git('init', '-q');