Framing: docs/persistence-framing.md. The four Rust primitives the
Lua-vs-Rust scout said were unavoidable, plus two Lua policy modules.
Rust:
- src/state.rs: state_dir(xdg,home) returning .../pmacs (generalizes
the baked-in history path). Deliberate empty-XDG fix (Q#PS2): a blank
XDG_STATE_HOME fell through to a RELATIVE pmacs/... path (a cwd-write
bug); now treated as absent so it falls to HOME. Confined key->file
store: validate_name rejects absolute / .. / empty / // / control
chars, plus a canonical-prefix belt; read/write/remove go through
file_io::save_atomic, never raw io.open. A PMACS_STATE_HOME override
lets CI / privacy-conscious users / integration harnesses redirect
all state to a scratch dir. History routed through the shared
resolver so it honors the override too.
- pmacs.state.{write,read,remove,path,available}: a no-op when the
state dir is unconfigured (cfg(test) / no HOME), so default-on
builtins write nothing in the lib suite. Configured once at startup
like history_dir, skipped under cfg(test).
- pmacs.editor.goto_byte / set_view_top: byte-exact restore (switch
zeroes the cursor).
Lua (builtin/runtime):
- saveplace.lua: record the active file's cursor+view_top on
before-save / before-quit; restore on after-load. LRU-capped places
state file. On by default; pmacs.saveplace.enable(false).
- recentf.lua: MRU record on after-load AND after-switch (re-visits
refresh the order); deduped/capped recentf file; a recent-files
command bound C-x C-r opens the minibuffer picker.
Tests: state.rs units (validate/resolve/round-trip/empty-XDG),
tests/persistence_acceptance.rs (state round-trip + confinement
rejections, inert-when-unconfigured, recentf MRU/dedup, saveplace
restore-on-reload, disable knob) injecting a tempdir state root. One
describe-hook test made robust to a builtin now subscribing to
buffer.before-save.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
