pardes FILE in a pane whose session answers never falls back to a nested editor: the refusal is printed, exit 1, and no stray pane is left

When the environment named a live session that answered, several
failures broke out of forwarding and started a whole editor inside the
pane that asked: a refused name, a pane the session has not, a failed look
write. Its screen was drawn over the shell. Now, once the session answers
(Client.probe), every refusal is printed as `pardes: <file>: <why>`, in
the session's own words (the Rerror, now kept by the client), and the
launch exits 1, as acme's B does. A new name the session refuses deletes
the pane made for it, so no empty +New is left. A missing environment or a
session that does not answer still starts a separate editor. fs.py checks
a refused name and a stale PARDES_PANE.

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

1 files changed, 16 insertions, 1 deletions

diff --git a/test/fs.py b/test/fs.py
index a6cd332e..98f46900 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -1219,11 +1219,18 @@ def test(binary, quic=False):
                     assert client.read('/index') == before
                     assert client.read('/pane/1/body') == b'initial\n'
 
+            # A session that answers takes the file or says why, as acme's B
+            # does: a pane it has not is its refusal and exit 1, never a
+            # nested editor drawn inside the pane that asked.
+            gone = subprocess.run([binary, '--tty', str(spaced)], cwd=root,
+                                  env=dict(env, PARDES_PANE='4294967295'), stdin=subprocess.DEVNULL,
+                                  stdout=subprocess.PIPE, stderr=subprocess.PIPE, timeout=10)
+            assert gone.returncode == 1 and gone.stderr.startswith(b'pardes: '), gone
+            assert client.read('/index') == before
             for name, identity, word in [
                 ('stale-file', dict(inherited, PARDES_9P=str(root / 'absent.sock')), str(spaced)),
                 ('stale-missing', dict(inherited, PARDES_9P=str(root / 'absent.sock')), 'missing-child-file.txt'),
                 ('stale-noarg', dict(inherited, PARDES_9P=str(root / 'absent.sock')), None),
-                ('stale-pane', dict(inherited, PARDES_PANE='4294967295'), str(spaced)),
                 # No pid means "not inside a pardes at all", which is what
                 # --nested withholds and what a plain shell has.
                 ('not-nested', {k: v for k, v in inherited.items() if k != 'PARDES_PID'}, str(spaced)),
@@ -1310,6 +1317,14 @@ def test(binary, quic=False):
             execute(client, named, 'Save')
             client.remove(f'/pane/{named}')
             assert deep.read_bytes() == b'deep\n'
+            # 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,
+                                     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 serials() == before, (serials(), before)
             orphan = launch('--wait')
             assert orphan.poll() is None
         assert orphan.wait(timeout=5) == 1