Handle document replacement during desktop integration checks

tools/check-desktop.py

@@ -84,11 +84,12 @@ with tempfile.TemporaryFile() as display_file, (ROOT / "logs/xvfb.log").open("w"
                 try:
                     # Wait for Marionette initialization before opening the suite.
                     with Client(2857) as client:
+                        connected = True
                         spec = importlib.util.spec_from_file_location("probe", ROOT / "tools/probe-desktop.py")
                         probe = importlib.util.module_from_spec(spec)
                         spec.loader.exec_module(probe)
                         probe.register(client)
-                        for _ in range(200):
+                        for _ in range(600):
                             ready = probe.evaluate(client, "system", "return document.body?.getAttribute('ready-state')==='fullyLoaded';")
                             if ready.get("value"):
                                 break

tools/test-host.py

@@ -102,7 +102,16 @@ bc.currentWindowGlobal.getActor('VulpesProbe').sendQuery('Evaluate', CODE)
             last = None
             deadline = time.monotonic() + timeout
             while time.monotonic() < deadline:
-                last = evaluate(app, code)
+                try:
+                    last = evaluate(app, code)
+                except AssertionError as error:
+                    # Navigation can replace the document while its read-only probe is pending.
+                    detail = error.args[0] if error.args else None
+                    if not isinstance(detail, dict) or not detail.get("error", "").startswith(
+                        "AbortError: Actor 'VulpesProbe' destroyed before query"
+                    ):
+                        raise
+                    last = None
                 if last:
                     return last
                 time.sleep(0.15)