1 files changed, 14 insertions, 0 deletions
diff --git a/test/fs.py b/test/fs.py
index 15f4eb8b..36ba180d 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -953,6 +953,20 @@ def test(binary, quic=False):
             with Client(address, msize=256) as small:
                 assert set(small.list('/os' + str(listing))) == {
                     f'entry-{number:02}' for number in range(24)}
+            # 64 KiB frames: a ctl line with no newline, whole in its one
+            # Twrite, runs with it however long -- the cutoff for a write
+            # that may go on is the frame the client asked for, less 24.
+            with Client(address, msize=65536) as big:
+                assert big.msize == 65536
+                ctl = big.open('/pane/1/ctl', 1)
+                line = b'bogus' + b'x' * 20000
+                try:
+                    big.rpc(118, struct.pack('<IQI', ctl, 0, len(line)) + line)
+                except OSError:
+                    pass  # refused with its write (a line over 1024 bytes), not held
+                else:
+                    raise AssertionError('a whole 20000-byte line waited for a newline')
+                big.close(ctl)
 
             frozen = client.open('/screen')
             before = bytearray(client.read_fid(frozen, count=31))