Devices: fixes from review round 21

- Behind a jump host, a forward it couldn't open moves on to the next address;
  only a refused key stops (judged by ssh's words, not the step).
- Add a headset suggests an alias no Host in ~/.ssh/config already uses.

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

tests/test_link.py

@@ -317,6 +317,15 @@ class Connecting(unittest.TestCase):
         self.assertFalse(fl.Link.is_target('Authenticated to bastion ([1.2.3.4]:22) using "publickey".', opts, "frame"))
         self.assertTrue(fl.Link.is_target('Authenticated to 10.0.0.5 ([10.0.0.5]:22) using "publickey".', opts, "frame"))
 
+    def test_a_forward_the_jump_host_couldnt_open_tries_the_next_address(self):
+        said = ["Authenticated to bastion ([1.2.3.4]:22) using \"publickey\".",
+                "channel 0: open failed: connect failed: Connection refused", "stdio forwarding failed"]
+        self.link.state["stages"] = [{"id": i, "state": "pending", "started": None, "ended": None, "detail": ""}
+                                     for i, _ in fl.STAGES]
+        self.assertEqual(self.link.failed("login", said, False, "frame"), "next")
+        self.assertEqual(self.link.failed("login", ["steamos@frame: Permission denied (publickey)."], False, "frame"),
+                         "stop")
+
     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")
@@ -528,6 +537,8 @@ class Connecting(unittest.TestCase):
         self.assertIn("frame-9", out["message"])
         self.assertEqual(out["active"], d["id"])
         self.assertEqual(fl.next_alias(self.link), "frame")
+        (self.dir / "ssh" / "config").write_text("Host frame lab-*\n  HostName 10.0.0.7\n")  # someone's own `frame`
+        self.assertEqual(fl.next_alias(self.link), "frame-2")
 
 
 @unittest.skipIf(os.name == "nt", "the stand-in ssh is a POSIX script")

ui/frame_link.py

@@ -914,7 +914,11 @@ class Link:
             self.fail("identity", "This address answered as a different headset (its SSH identity doesn't match). "
                       "If SteamOS was reinstalled, use Forget Identity on the Devices tab.", text)
             return "next"
-        if step == "login" or re.search(r"Permission denied", text):
+        # A refused key is the same at every address: stop. (Judged by ssh's own words, not
+        # the step: a jump host's progress lines look like the headset's.) A forward that
+        # a jump host couldn't open is about this address only: try the next.
+        forward = re.search(r"open failed|forwarding failed|Connection refused|Connection closed|timed out", text)
+        if re.search(r"Permission denied", text) and not forward:
             self.fail("login", self.explain(text) or "The headset didn't accept this computer's key.", text)
             return "stop"
         if step == "connected":
@@ -1141,8 +1145,15 @@ def devices_action(link, body, open_setup, busy=lambda: 0):
 
 
 def next_alias(link):
-    taken = {d["alias"] for d in link.reg.devices()} | {b["alias"] for b in frame_devices.parse_blocks(
+    """A free alias for a new headset: not one Frame Control knows, nor any `Host` name
-        frame_devices.read_config())}
+    already in ~/.ssh/config (Set Up Connection's block would shadow it)."""
+    text = frame_devices.read_config()
+    taken = {d["alias"] for d in link.reg.devices()} | {b["alias"] for b in frame_devices.parse_blocks(text)}
+    taken |= {a for a in (link.session_alias, link.override, link.active_device().get("alias")) if a}
+    for line in text.splitlines():
+        f = line.split()
+        if f and f[0].lower() == "host":
+            taken |= {name for name in f[1:] if not any(c in name for c in "*?!")}
     if "frame" not in taken:
         return "frame"
     n = 2