fix(tmux): bind nested prefix before unbind so an empty table cannot abort the chain

A user tmux config that leaves the prefix table empty makes
unbind-key -a -T prefix fail and drop later commands in the \; chain,
including send-prefix and remain-on-exit failed. Bind C-q send-prefix,
clear the table, then bind it again.

Also accept macOS ttys in the TUI switch-guard test without reading
/proc, and describe the client_pid hook escape as defensive on tmux 3.4.

Co-authored-by: DDT <1786035110@qq.com>

src/tmux-manager.ts

@@ -1230,7 +1230,8 @@ export function remoteTmuxLocation(remote: SessionRemote, sessionId: string): {
  *     'tmux -L codeman-remote new-session -A -s codeman-ssh-<id> -c <path> "cd <path> && exec <cli>" \
  *        \; set -t codeman-ssh-<id> status off \; set -t codeman-ssh-<id> mouse off \
  *        \; set -t codeman-ssh-<id> prefix C-q \; set -s escape-time 0 \; \
- *        unbind-key -a -T prefix \; bind-key -T prefix C-q send-prefix'
+ *        bind-key -T prefix C-q send-prefix \; unbind-key -a -T prefix \; \
+ *        bind-key -T prefix C-q send-prefix'
  *
  * COD-107 — the connection options (`-p`, `-i`, `-J`, SOCKS `-o ProxyCommand`,
  * arbitrary `-o`) come from the shared `buildSshConnectionArgs(remote)`, so the
@@ -1356,9 +1357,11 @@ export function buildRemoteLaunchCommand(options: {
     // The prefix TABLE is server-global (unlike `prefix C-q`, which is per
     // session). This socket is dedicated to Codeman's owned sessions, so the
     // same reduction as the local socket applies: Ctrl+Q then )/(/s/w/L must
-    // not switch-client / choose-tree onto a sibling. BEFORE remain-on-exit,
-    // which stays last because an old remote tmux rejects `failed` and aborts
-    // the rest of the chain.
+    // not switch-client / choose-tree onto a sibling. Bind, then unbind-all,
+    // then bind again: a user config that left the prefix table empty makes
+    // `unbind-key -a -T prefix` fail and abort the rest of this chain.
+    // BEFORE remain-on-exit, which stays last because an old remote tmux
+    // rejects `failed` and aborts the rest of the chain.
     ...nestedPrefixTableResetCommands(),
     // #210: keep a CRASHED pane so the failure is still on screen. Without this,
     // tmux destroys the pane -> window -> session (and, being the only session,

src/tmux-prefix-table.ts

@@ -63,11 +63,21 @@ export const NESTED_TMUX_PREFIX = 'C-q';
  * Joined with `\;` onto the `new-session` that creates the server
  * (`buildRemoteLaunchCommand`, `buildDockerLaunchCommand`). No `tmux` binary
  * and no `-g`: the table is server-global, which is what we want on these
- * dedicated sockets and nowhere else. Put them BEFORE `remain-on-exit failed`
- * so a remote tmux that rejects `failed` does not drop the reduction.
+ * dedicated sockets and nowhere else.
+ *
+ * Those servers load the user's tmux config (no `-f /dev/null`). A config that
+ * leaves the prefix table empty makes `unbind-key -a -T prefix` fail with
+ * "table prefix doesn't exist", and tmux then drops every later command in the
+ * `\;` chain, including the bind and `remain-on-exit failed` (#210). The same
+ * empty table is what #669 handled on the local socket. Binding `send-prefix`
+ * first creates the table so the unbind can run; the unbind clears stock
+ * bindings (and that first bind); the second bind puts `send-prefix` back.
+ * Put them BEFORE `remain-on-exit failed` so a remote tmux that rejects
+ * `failed` does not drop the reduction.
  */
-export function nestedPrefixTableResetCommands(): readonly [string, string] {
-  return ['unbind-key -a -T prefix', `bind-key -T prefix ${NESTED_TMUX_PREFIX} send-prefix`];
+export function nestedPrefixTableResetCommands(): readonly [string, string, string] {
+  const sendPrefix = `bind-key -T prefix ${NESTED_TMUX_PREFIX} send-prefix`;
+  return [sendPrefix, 'unbind-key -a -T prefix', sendPrefix];
 }
 
 /** One `list-keys -T prefix` line: key and command. */

src/tui/tui-client.ts

@@ -491,9 +491,11 @@ export function tuiSwitchGuard(tty: string): string {
 }
 
 /**
- * `set-hook` command for `TUI_SWITCH_ATTACH_HOOK`. `\#{client_pid}` is deferred
- * so tmux expands it when the hook fires, not when the hook is stored (a bare
- * `#{client_pid}` is expanded at `set-hook` time, in no client, and stored empty).
+ * `set-hook` command for `TUI_SWITCH_ATTACH_HOOK`. `\#{client_pid}` is
+ * defensive. On tmux 3.4 both this form and a bare `#{client_pid}` are stored
+ * verbatim and both record the attaching client's pid. The escape stays so a
+ * tmux that expands formats while the hook is stored (no client exists yet)
+ * cannot save an empty pid.
  */
 export function tuiSwitchAttachHook(tty: string): string {
   return (