fs.py waits for a new file's pane to be named, not only made

pardes --wait NEWFILE reads pane/new and then writes the pane's name, two requests; the test checked /index for the name as soon as the pane showed, and a gate run caught it between them. It waits for the name now.

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

1 files changed, 4 insertions, 3 deletions

diff --git a/test/fs.py b/test/fs.py
index 36ba180d..06643385 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -1281,13 +1281,14 @@ def test(binary, quic=False):
             before = serials()
             made = subprocess.Popen([binary, '--wait', fresh.name], cwd=root, env=env,
                                     stdout=subprocess.DEVNULL, stderr=subprocess.PIPE)
+            # The launch makes the pane (pane/new), then names it: wait for
+            # the name, not the pane.
             deadline = time.monotonic() + 3
-            while not serials() - before:
+            while str(fresh).encode() not in client.read('/index'):
                 assert made.poll() is None, made.stderr.read()
-                assert time.monotonic() < deadline, 'a new name opened no pane'
+                assert time.monotonic() < deadline, 'a new name opened no pane named it'
                 time.sleep(.01)
             named, = serials() - before
-            assert str(fresh).encode() in client.read('/index')
             client.write(f'/pane/{named}/body', b'new\n')
             execute(client, named, 'Save')
             client.remove(f'/pane/{named}')