write a pane's options in one tmux command list

the watcher wrote @agent_state, then @dingger_hook, as separate tmux
calls. a daemon stopped between them left a done display state next to a
stale "working" hook state, which the restarted daemon trusted: the agent
came back as working. now every changed option of a pane is one command
list, which tmux applies as a unit (and one process instead of several).

tests/kill-race.sh kills the daemon the instant an agent shows done: 24 of
40 kills left the options inconsistent before, 0 of 40 now. e2e step 17
runs it 20 times; the previous binary fails it.

1 files changed, 19 insertions, 0 deletions

diff --git a/crates/dinggerd/src/tmux.rs b/crates/dinggerd/src/tmux.rs
index b1a2d60..182d62f 100644
--- a/crates/dinggerd/src/tmux.rs
+++ b/crates/dinggerd/src/tmux.rs
@@ -229,6 +229,25 @@ pub fn set_pane_option(pane_id: &str, name: &str, value: &str) -> Result<(), Str
     run_tmux(&["set-option", "-p", "-t", pane_id, name, value]).map(|_| ())
 }
 
+/// Set (`Some`) or unset (`None`) several pane options in one tmux command
+/// list, applied as a unit.
+pub fn set_pane_options(pane_id: &str, changes: &[(&str, Option<String>)]) -> Result<(), String> {
+    let mut args: Vec<&str> = Vec::new();
+    for (name, value) in changes {
+        if !args.is_empty() {
+            args.push(";");
+        }
+        match value {
+            Some(value) => args.extend(["set-option", "-p", "-t", pane_id, name, value.as_str()]),
+            None => args.extend(["set-option", "-p", "-u", "-t", pane_id, name]),
+        }
+    }
+    if args.is_empty() {
+        return Ok(());
+    }
+    run_tmux(&args).map(|_| ())
+}
+
 pub fn unset_pane_option(pane_id: &str, name: &str) -> Result<(), String> {
     run_tmux(&["set-option", "-p", "-u", "-t", pane_id, name]).map(|_| ())
 }