fix(node): index, serve and write files past Windows' MAX_PATHHEADmain

With the system's default setting (LongPathsEnabled off) every call given
a plain path of 260 characters or more refuses it, so a deep library was
partly invisible: the walk could not list such a directory and its files
never reached the members.

The node now hands each call that touches a group's disk the extended
form (paths.long_path), and keeps the plain path in the index, the hash
cache and the log. A directory is listed under its long form and its
entries named from the plain one (indexer.walk_files, wire._walk_dirs).
Covered: the walk, stats and hashing, reconcile and the watcher, the
folder list members see, serving over WebRTC and QUIC, deletion, uploads
and their recovery, folder creation and removal, audio tags and the
cover beside a track, photos, and a show's episode numbering. ffmpeg
extends a long path itself and keeps the plain one.

long_path now normalises before prefixing (the extended form skips the
system's normalisation) and starts at 248 characters, where creating a
directory is already refused.

test_long_paths.py runs with the setting off: 15 of its 17 tests fail
without the change. Checked by hand in the installed app with files at
312 to 380 characters.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/roots.py b/packages/meshbay-node/src/meshbay_node/roots.py
index 61fdc9b..94560f5 100644
--- a/packages/meshbay-node/src/meshbay_node/roots.py
+++ b/packages/meshbay-node/src/meshbay_node/roots.py
@@ -36,7 +36,7 @@ from concurrent.futures import ThreadPoolExecutor
 from dataclasses import dataclass, field
 from pathlib import Path
 
-from meshbay_common.paths import fold, portable_name_problem
+from meshbay_common.paths import fold, long_path, portable_name_problem
 
 log = logging.getLogger(__name__)
 
@@ -78,7 +78,7 @@ def _free_name(directory: Path, filename: str,
     or another upload (C5a).
     """
     def free(name: str) -> bool:
-        return name not in taken and not (directory / name).exists()
+        return name not in taken and not os.path.exists(long_path(directory / name))
 
     if free(filename):
         return filename
@@ -109,17 +109,17 @@ def publish_upload(part: Path, directory: Path, stored_name: str, filename: str,
     for _ in range(8):
         target = directory / name
         try:
-            os.link(part, target)
+            os.link(long_path(part), long_path(target))
         except FileExistsError:
             name = _free_name(directory, filename, taken)
             continue
         except OSError:
-            if target.exists():
+            if os.path.exists(long_path(target)):
                 name = _free_name(directory, filename, taken)
                 continue
-            part.rename(target)
+            os.rename(long_path(part), long_path(target))
             return name
-        part.unlink()
+        os.unlink(long_path(part))
         return name
     raise FileExistsError(stored_name)
 
@@ -195,7 +195,7 @@ class Root:
     def is_live(self) -> bool:
         """Readable right now. The question `available` caches."""
         try:
-            return self.path.is_dir()
+            return os.path.isdir(long_path(self.path))
         except OSError:
             return False