Devices: fixes from review round 17

- A command that fails after a switch doesn't make the connector drop the new
  headset's connection.
- On first import, the app keeps using the `frame` headset even when Set Up
  Connection put another block above it.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

tests/test_devices.py

@@ -113,6 +113,17 @@ class Migration(Base):
         self.assertEqual(len(data["devices"]), 2)
         self.assertEqual(fd.Registry(self.dir / "devices.json").devices(), self.reg.devices())
 
+    def test_first_import_keeps_using_frame(self):
+        # Set Up Connection puts each new block first; the app used `frame` before.
+        blocks = CONFIG.split("# >>> steam-frame (frame-2) >>>")
+        head, first = blocks[0].split("# >>> steam-frame (frame) >>>")
+        second, tail = blocks[1].split("# <<< steam-frame (frame-2) <<<")
+        (self.ssh / "config").write_text(head + "# >>> steam-frame (frame-2) >>>" + second + "# <<< steam-frame (frame-2) <<<\n"
+                                         + "# >>> steam-frame (frame) >>>" + first + tail)
+        self.reg.sync_from_config(seed=False)
+        self.assertEqual([d["alias"] for d in self.reg.devices()], ["frame-2", "frame"])
+        self.assertEqual(self.reg.active(), self.reg.by_alias("frame")["id"])
+
     def test_setup_finding_a_new_address_adds_it(self):
         self.reg.sync_from_config(seed=False)
         (self.ssh / "config").write_text(CONFIG.replace("HostName frame.tail1234.ts.net", "HostName 192.168.1.237"))

tests/test_link.py

@@ -304,6 +304,14 @@ class Connecting(unittest.TestCase):
         self.assertIn("User deck", cfg.read_text())  # changed meanwhile: left as it is
         self.assertIn("left as it is", out["message"])
 
+    def test_a_late_failure_from_the_last_headset_is_ignored(self):
+        self.link.state["phase"] = "connected"
+        self.link.gen = 3
+        self.link.lost("ssh: connect to host a port 22: Operation timed out", 2)  # sent before the switch
+        self.assertEqual(self.link.kicks, [])
+        self.link.lost("ssh: connect to host b port 22: Operation timed out", 3)
+        self.assertEqual(len(self.link.kicks), 1)
+
     def test_probes_from_an_earlier_attempt_leave_the_new_rows_alone(self):
         self.link.state.update(attempt=2, probes=[{"host": "b", "state": "waiting"}])
         self.link.probe_update(0, 1, state="answered", ip="10.0.0.2")

ui/frame_devices.py

@@ -672,6 +672,7 @@ class Registry:
         blocks = parse_blocks(read_config(self.config))
         changed = False
         with self.lock:
+            first = not self.data["devices"] and not self.data.get("active")
             for b in blocks:
                 host = b["hostname"] if b["hostname"] and HOST_RE.fullmatch(b["hostname"]) else None
                 user = b["user"] if b["user"] and NAME_RE.fullmatch(b["user"]) else DEFAULT_USER
@@ -714,6 +715,13 @@ class Registry:
             aliases = {b["alias"] for b in blocks}
             for d in self.data["devices"]:
                 d["managed"] = d["alias"] in aliases
+            if first:
+                # First import: the headset the app used before is `frame`, even if Set Up
+                # Connection put another block above it.
+                frame = next((d for d in self.data["devices"] if d["alias"] == "frame"), None)
+                if frame and self.data.get("active") != frame["id"]:
+                    self.data["active"] = frame["id"]
+                    changed = True
             if changed:
                 self.save()
         return changed

ui/frame_link.py

@@ -325,8 +325,12 @@ class Link:
     def route_key(device):
         return device["id"], device.get("user"), device.get("port"), tuple(device.get("frozen") or ())
 
-    def lost(self, message):
-        """A command couldn't reach the headset (Windows has no master to watch)."""
+    def lost(self, message, gen=None):
+        """A command couldn't reach the headset (Windows has no master to watch). `gen`:
+        the route it was sent on; one to a headset since switched away from says nothing
+        about this one."""
+        if gen is not None and gen != self.gen:
+            return
         if self.state["phase"] == "connected":
             self.kick(f"lost: {message}")
 

ui/server.py

@@ -254,6 +254,7 @@ def ensure_master():
 
 
 def ssh(remote, *, stdin=None, timeout=30, text=True):
+    route_gen = LINK.gen if LINK else None  # which headset this command is for
     try:
         ensure_master()
         # Never let ssh inherit our stdin: under the app it's the pipe held open for
@@ -266,7 +267,7 @@ def ssh(remote, *, stdin=None, timeout=30, text=True):
     if r.returncode != 0:
         err = (r.stderr or r.stdout) if text else (r.stderr or r.stdout).decode(errors="replace")
         if r.returncode == 255 and LINK and unreachable(err):
-            LINK.lost(err)  # ssh itself failed: the connector reconnects
+            LINK.lost(err, route_gen)  # ssh itself failed: the connector reconnects
         failure = Failure(strip_ansi(err).strip() or f"ssh exited {r.returncode}")
         failure.stdout = r.stdout if text else r.stdout.decode(errors="replace")
         raise failure