A Restore answers its writer before hanging up, and the log records dumps and restores

A client that wrote Restore saw its connection cut with no answer, and could
not tell a Restore from a crash. The listener now lets the writer's answer out
before the cut, and cuts only the old editor's connections, refusing their
requests meanwhile; a client that dials during it is the new editor's and
stays. Dump logs 'dump <path>' and the restored editor's log 'restore <path>'.
Keeping connections across a Restore was weighed and left: the fids name the
old editor's panes and opens, so it would mean carrying serials and open
records into the new one, where acme's Load only adds windows. tty's Restore
also closed its shells' ptys without reaping them; it retires them now.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 16 insertions, 4 deletions

diff --git a/docs/fs.md b/docs/fs.md
index a2d8a9b2..f377d32a 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -84,7 +84,8 @@ Existing Plan9port/v9fs clients need a userspace bridge for QUIC.
 /status      pid, version and pane count
 /look        write a line: a right click on it at the active pane; read: the serials it touched
 /exec        write a line: a middle click; read the same serials
-/log         recent events, one a line: new|del|rename|save <serial> <name>, msg <serial|-> <text>;
+/log         recent events, one a line: new|del|rename|save <serial> <name>, msg <serial|-> <text>,
+             dump|restore <path>, err <serial|-> <file>: <why>;
              write follow to that open to wait for more
 /screen      rendered screen JSON; frozen per open handle
 /listeners   the session's dial addresses
@@ -106,8 +107,17 @@ builtins, one a line, at whichever pane has the keyboard as each runs --
 `Newcol`, `Dump`, `Mount name dial`, `Theme ink`, `Verbose off`; `Exit`,
 which quits the editor as acme's does (it refuses once, naming each pane with
 unsaved text, `<name>: Modified (Exit again to discard)`, and a second
-`Exit` with nothing edited since quits, throwing that text away; a scratch under 100 bytes is not asked about; `Restore`, which
-replaces every pane, asks the same first); and `Kill`, which
+`Exit` with nothing edited since quits, throwing that text away; a scratch
+under 100 bytes is not asked about; `Restore`, which replaces every pane,
+asks the same first -- `Dump` writes `pardes-<date>-<time>.zon` in
+`DumpDir` (default `$XDG_DATA_HOME/pardes`, else `~/.local/share/pardes`)
+and logs `dump <path>`, and `Restore` with no path takes the last one; a
+Restore puts a new editor under every client, so the write of it is
+answered and then every connection is hung up, their fids naming the old
+editor's panes: dial again, and the new log names the restored panes and
+`restore <path>`. Keeping connections across it would mean carrying serials
+and opens into the new editor, which acme, whose Load only adds windows,
+never needed); and `Kill`, which
 does not quit but stops commands, as acme's does: bare, every command pardes
 started, and `Kill make ls`, those whose line begins with one of the words. A
 command pardes started is a line it typed into a terminal (a word written to
@@ -333,7 +343,9 @@ an open renders its frame; stat the entry.
 
 `/log` is one ring (64 KiB) that records whether or not anyone reads it:
 `new`, `del`, `rename` (a terminal's too, as its shell changes directory,
-since a terminal is named by its directory) and `save <serial> <name>`, and `msg <serial|-> <text>`
+since a terminal is named by its directory) and `save <serial> <name>`,
+`dump <path>` when a Dump is written and `restore <path>` in a Restore's
+new log after its panes' `new`s, and `msg <serial|-> <text>`
 for every line the editor says, repeats included (with `verbose` on, that
 includes each builtin announcing itself as it runs), and `err <serial|->
 <file>: <why>` for every write or truncation the tree refused or that