name takes any byte a file name can hold, controls, edge blanks and bytes not UTF-8 included, so what name reads writes back as it was

A pane opened on a file whose name held a tab, a control byte or bytes
not UTF-8 read that name from its name file, and the same bytes written
back were refused. Only what no file name holds is refused now: a second
line and a NUL. The ctl word name still refuses a second blank after the
word, as a line's words are split at blanks.

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

1 files changed, 2 insertions, 2 deletions

diff --git a/test/fs.py b/test/fs.py
index 7061c61f..ba43c606 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -1386,10 +1386,10 @@ def test(binary, quic=False):
             # A name the session refuses: its reason and exit 1, as B's,
             # never a nested editor, and no pane left for it.
             before = serials()
-            refused = subprocess.run([binary, 'bad\x01name.txt'], cwd=root, env=env,
+            refused = subprocess.run([binary, 'x' * 300 + '.txt'], cwd=root, env=env,
                                      stdout=subprocess.PIPE, stderr=subprocess.PIPE, timeout=10)
             assert refused.returncode == 1, refused
-            assert b'bad character in file name' in refused.stderr, refused.stderr
+            assert b'a component over 255 bytes' in refused.stderr, refused.stderr
             assert serials() == before, (serials(), before)
             # A pane address the session has not is refused in words, exit
             # 1, no pane made for a file of that name; one it has is looked