A REPL paste's Enter waits on the clock, not on stale core time

sendToRepl timed the Enter's fallback from stepped_ns, which in an idle
detached session is as old as the last frame: the wait was over before it
began and the \r went out with the paste, which 3.13's REPL then reads as
part of it (4 of 5 sends lost their Enter). The wait now starts from the
host's clock and is checked against now_ns; the REPL's echo of the paste
still sends it sooner, and the wake is scheduled for the deadline. fs.py
sends five times after two idle seconds each in a real pty.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/test/fs.py b/test/fs.py
index 9336a53a..bac7020c 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -515,6 +515,14 @@ def python_repl_runs_one_line(binary):
                 record = b'MX0 0 0 10 print(6*7)\n'
                 client.rpc(118, struct.pack('<IQI', fid, 0, len(record)) + record)
                 assert wait_for('\n42'), body()
+                # After the session has sat idle, the Enter still waits for
+                # the paste: core time is as old as the last frame then.
+                for n in range(5):
+                    time.sleep(2)
+                    line = f'print({1000 + n})'.encode()
+                    record = b'MX0 0 0 %d %s\n' % (len(line), line)
+                    client.rpc(118, struct.pack('<IQI', fid, 0, len(record)) + record)
+                    assert wait_for(f'\n{1000 + n}'), (n, body())
             finally:
                 client.close(fid)