The unreadable-config-overwrite bug (an existing config.yaml that reads as
{} on a permission/IO error gets replaced with only defaults or the edited
section) is not limited to save_config / config set / auth. The same
read-then-atomic_yaml_write pattern lives at ~7 other independent write
sites that don't route through those functions:
- gateway/slash_commands.py: _save_config_key, memory/skills write_approval
toggles, tool_progress toggle, runtime_footer toggle, personality set
- hermes_cli/doctor.py --fix (stale root-key migration)
- gateway/platforms/yuanbao.py auto-sethome
- plugins/platforms/telegram/adapter.py topic thread_id persistence
- tui_gateway/server.py _save_cfg
- agent/onboarding.py mark_seen
Rather than sprinkle require_readable_config_before_write() at each site,
add a single fail-closed chokepoint, atomic_config_write(), that runs the
guard then delegates to atomic_yaml_write, and route every config.yaml
write through it. Root cause remains that read_raw_config() can't tell an
absent file from an unreadable one (returns {} for both) — read-only
callers correctly stay fail-open, but any full-file replacement now fails
closed in one enforced place instead of relying on each caller to remember
the guard.
save_config / set_config_value / auth keep the contributor's original
guard calls (their commit); this commit widens the fix to the sibling
call paths and adds a regression test on the chokepoint (fails closed on
unreadable existing file + still creates a genuinely absent file).
123c6f3a23