From 449f6bef8cfd3bb2c1fc4caa5d334ea95893d253 Mon Sep 17 00:00:00 2001
From: Chris Tate <chris@ctate.dev>
Date: Sun, 4 Oct 2026 09:14:08 -0500
Subject: [PATCH] Preserve Windows errors when following filesystem links

---
 packages/runtime/src/scr_lib.c             | 19 +++++++++++++++----
 tests/corpus/node24-fs-links-callbacks.cjs |  4 +++-
 tests/corpus/node24-fs-links.ts            |  9 +++++++++
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/packages/runtime/src/scr_lib.c b/packages/runtime/src/scr_lib.c
index b355a4c31..0377e5a4c 100644
--- a/packages/runtime/src/scr_lib.c
+++ b/packages/runtime/src/scr_lib.c
@@ -4243,8 +4243,21 @@ static ScrStats *scr_stats_of_path(const ScrStr *path, const char *op,
   HANDLE h = CreateFileW(wide, FILE_READ_ATTRIBUTES,
                          FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
                          NULL, OPEN_EXISTING, flags, NULL);
+  if (h == INVALID_HANDLE_VALUE) {
+    DWORD error = GetLastError();
+    DWORD attributes = GetFileAttributesW(wide);
+    free(wide);
+    /* CRT stat can report the link entry when its target cannot be opened,
+     * hiding dangling links and Windows file/directory type mismatches.
+     * libuv preserves the failed follow operation for reparse points. */
+    if (!no_follow && attributes != INVALID_FILE_ATTRIBUTES &&
+        (attributes & FILE_ATTRIBUTE_REPARSE_POINT)) {
+      scr_fs_throw(scr_fs_win_errno(error), op, path);
+      return NULL;
+    }
+    return scr_stats_crt_fallback(path, op);
+  }
   free(wide);
-  if (h == INVALID_HANDLE_VALUE) return scr_stats_crt_fallback(path, op);
 
   DWORD file_type = GetFileType(h);
   if (file_type != FILE_TYPE_DISK) {
@@ -4423,9 +4436,7 @@ void scr_fs_symlink(ScrStr *target, ScrStr *destination, int kind) {
     free(text);
   }
   scr_str_release(absolute);
-  /* Node's binding namespaces the link path before passing it to libuv.
-   * In particular, Windows can reject a file link to a directory differently
-   * when the destination uses the extended-length path syntax. */
+  /* Node's binding namespaces the link path before passing it to libuv. */
   ScrStr *link_path = scr_path_win32_to_namespaced_path(destination);
   WCHAR *from = scr_fs_win_wide(stored), *to = scr_fs_win_wide(link_path);
   DWORD error = !from || !to ? GetLastError() : 0;
diff --git a/tests/corpus/node24-fs-links-callbacks.cjs b/tests/corpus/node24-fs-links-callbacks.cjs
index 5002c7611..ed834af33 100644
--- a/tests/corpus/node24-fs-links-callbacks.cjs
+++ b/tests/corpus/node24-fs-links-callbacks.cjs
@@ -38,7 +38,9 @@ async function main() {
     // Buffer paths bypass that probe and use the file-link fallback.
     try {
       await call(fs.symlink, "dir", Buffer.from(join(root, "inferred")));
-      console.log("inferred", fs.statSync(join(root, "inferred")).isDirectory());
+      console.log("inferred link", fs.lstatSync(join(root, "inferred")).isSymbolicLink());
+      try { console.log("inferred stat", fs.statSync(join(root, "inferred")).isDirectory()); }
+      catch (e) { console.log("inferred stat", e.name, e.code, e.message.includes("stat")); }
     } catch (e) { if (process.platform === "win32" && e.code === "EPERM") console.log("symlink privilege boundary"); else throw e; }
     let synchronous = true;
     await new Promise(resolve => {
diff --git a/tests/corpus/node24-fs-links.ts b/tests/corpus/node24-fs-links.ts
index 18d1ec2ef..043eb309e 100644
--- a/tests/corpus/node24-fs-links.ts
+++ b/tests/corpus/node24-fs-links.ts
@@ -32,8 +32,17 @@ try {
     console.log("absolute", fs.readlinkSync(join(root, "absolute")) === file);
     fs.symlinkSync("missing-target", join(root, "dangling"), null);
     console.log("dangling", fs.readlinkSync(join(root, "dangling")), fs.lstatSync(join(root, "dangling")).isSymbolicLink());
+    try { fs.statSync(join(root, "dangling")); } catch (e) { const err = e as NodeJS.ErrnoException; console.log("dangling stat", err.name, err.code); }
     fs.symlinkSync("nested", join(root, "directory"), "dir");
     console.log("directory", fs.statSync(join(root, "directory")).isDirectory());
+    fs.symlinkSync("nested", join(root, "file-directory"), "file");
+    console.log("file-directory link", fs.lstatSync(join(root, "file-directory")).isSymbolicLink(), fs.readlinkSync(join(root, "file-directory")) === "nested");
+    try { console.log("file-directory stat", fs.statSync(join(root, "file-directory")).isDirectory()); }
+    catch (e) { const err = e as NodeJS.ErrnoException; console.log("file-directory stat", err.name, err.code); }
+    fs.symlinkSync("target.txt", join(root, "directory-file"), "dir");
+    console.log("directory-file link", fs.lstatSync(join(root, "directory-file")).isSymbolicLink());
+    try { console.log("directory-file stat", fs.statSync(join(root, "directory-file")).isFile()); }
+    catch (e) { const err = e as NodeJS.ErrnoException; console.log("directory-file stat", err.name, err.code); }
     if (process.platform !== "win32") {
       fs.symlinkSync("x".repeat(600), join(root, "long"), "file");
       console.log("long", fs.readlinkSync(join(root, "long")).length);