test: the lost-link test waits for the armed marker instead of fixed timers

src/client.rs

@@ -2077,7 +2077,12 @@ mod remote_tests {
             // As the real client: a relay that fails at once may close the pipe before Hello.
             let _ = hello().write_to(&mut stdin);
             let mut screen = Vec::new();
-            let seen = pump(Vec::new(), stdout, &mut screen, false, |_| {});
+            // The `lost` fake cuts the link only once the client has the marker.
+            let seen = pump(Vec::new(), stdout, &mut screen, false, |r| {
+                if r.armed {
+                    let _ = std::fs::write(self.dir.join("armed"), "");
+                }
+            });
             drop(stdin);
             let (exit, said) = finish(child, stderr);
             (seen, screen, exit, said)
@@ -2273,8 +2278,14 @@ mod remote_tests {
     #[test]
     fn a_link_that_dies_after_the_arming_is_a_loss() {
         let fake = Fake::new("lost", "lost");
-        let server = fake.serve(|s| {
+        let armed = fake.dir.join("armed");
+        let server = fake.serve(move |s| {
             s.write_all(ARMED).unwrap();
+            // Open until the client has the marker, however slow the machine, then long enough for the fake ssh to cut the link.
+            let t = std::time::Instant::now();
+            while !armed.exists() && t.elapsed() < Duration::from_secs(60) {
+                std::thread::sleep(Duration::from_millis(20));
+            }
             std::thread::sleep(Duration::from_secs(3));
         });
         let (seen, _, exit, said) = fake.run("1");

tests/fixtures/fake-ssh

@@ -21,11 +21,11 @@ case $last in
     unset NERD_SOCKET NERD_INSTANCE
     export NERD_STATE_DIR="$dir/state" HOME="$dir"
     if [ "$mode" = lost ]; then
-        # The link drops a second in: the relay dies with no word, ssh exits 255.
+        # The link drops once the client has the armed marker: the relay dies with no word, ssh exits 255.
         "$dir/nerd" --relay "$id" <&0 &
         pid=$!
-        sleep 1
-        kill -9 $pid
+        while [ ! -e "$dir/armed" ] && kill -0 $pid 2>/dev/null; do sleep 0.05; done
+        kill -9 $pid 2>/dev/null
         : > "$dir/ended"
         exit 255
     fi