1 files changed, 27 insertions, 8 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/transport/wire.py b/packages/meshbay-node/src/meshbay_node/transport/wire.py
index 77c5d62..75d27c1 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/wire.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/wire.py
@@ -32,6 +32,7 @@ from pathlib import Path
 
 from meshbay_common import MNP_VERSION
 from meshbay_common.groupbox import PURPOSE_INDEX, seal
+from meshbay_common.paths import long_path
 from meshbay_common.protocol import MNP, index_entry_wire
 
 from meshbay_node.roots import RootSet, off_disk
@@ -75,22 +76,40 @@ def _dir_roots(roots: RootSet) -> list[tuple[str, Path, bool]]:
 
 
 def _walk_dirs(dir_roots: list[tuple[str, Path, bool]]) -> list[str]:
-    """Blocking. Directories only: `os.walk` reads each one once and never
-    stats a file, which `rglob("*")` and an `is_dir()` per entry did."""
+    """Blocking. Directories only: each is read once and no file is stat'ed,
+    which `rglob("*")` and an `is_dir()` per entry did. What `os.walk` did,
+    except that each directory is listed under its long form: `os.walk` skipped
+    whatever lay past Windows' MAX_PATH, without a word."""
     out: list[str] = []
     for name, path, available in dir_roots:
         out.append(name)
         if not available:
             continue
-        for top, subdirs, _files in os.walk(path):
-            # Pruned in place: nothing under a hidden directory is listed either.
-            subdirs[:] = [d for d in subdirs if not d.startswith(".")]
-            rel = Path(top).relative_to(path)
-            for d in subdirs:
-                out.append(f"{name}/{(rel / d).as_posix()}")
+        pending = [path]
+        while pending:
+            top = pending.pop()
+            try:
+                with os.scandir(long_path(top)) as listing:
+                    # Nothing under a hidden directory is listed either.
+                    subdirs = [e for e in listing
+                               if not e.name.startswith(".") and _is_dir(e)]
+            except OSError:
+                continue
+            rel = top.relative_to(path)
+            for entry in subdirs:
+                out.append(f"{name}/{(rel / entry.name).as_posix()}")
+                if not entry.is_symlink():      # listed, not entered, as os.walk did
+                    pending.append(top / entry.name)
     return sorted(out)[:MAX_DIRS]
 
 
+def _is_dir(entry: os.DirEntry) -> bool:
+    try:
+        return entry.is_dir()
+    except OSError:
+        return False
+
+
 def index_sync_message(index, roots: RootSet | None, hidden=(),
                        dirs: list[str] | None = None) -> dict:
     """