* fix: keep the conf intact when writing it fails
_setopt() and _clear_conf() redirected the new content straight into the
conf file. The redirect truncates the file before anything is written,
so a failed write (no space left on device, quota, I/O error) left a
0-byte conf, _save_conf still returned 0, and the cert could not be
renewed any more even after space was freed.
Write the new content to a temp file next to the conf, verify it, then
rename it over the conf. The temp file is created with cp -p so the mode
and owner are kept. A symlinked or bind mounted conf cannot be renamed
over, so it is written in place once the temp copy is known to be good.
A failed write now returns 1 with an error and the conf untouched.
Fixes#7247
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RL9G1DHE5yNVtkm3FFPPNX
* fix: route the append through _write_conf and keep the temp file on a failed in-place write
The append branch of _setopt() still wrote into the conf with >>, so a
write cut short (full disk, quota) left a half written line while
_setopt returned 0, and sourcing the conf failed afterwards. Build the
new content in all three branches and write it once through _write_conf.
This also drops the separate trailing newline append.
In the symlink / bind mount fallback, a failed in-place write leaves the
conf truncated. Keep the temp file in that case, since it is the only
complete copy, and name it in the error.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01G7ohY7h4RUSNJ2ES14NMmY
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Co-authored-by: Claude Fable 5.1 <noreply@anthropic.com>
