race condition: input thread must wait for curses_init() to complete

xpra/client/base/top_client.py

@@ -7,7 +7,7 @@
 import curses
 import signal
 import traceback
-from time import monotonic
+from time import monotonic, sleep
 from subprocess import Popen, PIPE, DEVNULL
 from datetime import datetime, timedelta
 from typing import Dict, Tuple
@@ -473,6 +473,9 @@ def update_screen(self):
     def input_thread(self):
         self.log(f"input thread: signal handlers={signal.getsignal(signal.SIGINT)}")
         while self.exit_code is None:
+            if not self.stdscr:
+                sleep(0.1)
+                continue
             if not self.paused and self.modified:
                 self.stdscr.erase()
                 try: