fix(runtime): allow nul device on windows (#23741)

Fixes [23721](https://github.com/denoland/deno/issues/23721)

3 files changed, 19 insertions, 4 deletions

diff --git a/ext/fs/std_fs.rs b/ext/fs/std_fs.rs
index 6bc15a72d..9e2acedcc 100644
--- a/ext/fs/std_fs.rs
+++ b/ext/fs/std_fs.rs
@@ -890,7 +890,15 @@ fn open_with_access_check(
   access_check: Option<AccessCheckCb>,
 ) -> FsResult<std::fs::File> {
   if let Some(access_check) = access_check {
-    let path = if path.is_absolute() {
+    let path_bytes = path.as_os_str().as_encoded_bytes();
+    let is_windows_device_path = cfg!(windows)
+      && path_bytes.starts_with(br"\\.\")
+      && !path_bytes.contains(&b':');
+    let path = if is_windows_device_path {
+      // On Windows, normalize_path doesn't work with device-prefix-style
+      // paths. We pass these through.
+      path.to_owned()
+    } else if path.is_absolute() {
       normalize_path(path)
     } else {
       let cwd = current_dir()?;
@@ -898,8 +906,8 @@ fn open_with_access_check(
     };
     (*access_check)(false, &path, &options)?;
     // On Linux, /proc may contain magic links that we don't want to resolve
-    let needs_canonicalization =
-      !cfg!(target_os = "linux") || path.starts_with("/proc");
+    let needs_canonicalization = !is_windows_device_path
+      && (!cfg!(target_os = "linux") || path.starts_with("/proc"));
     let path = if needs_canonicalization {
       match path.canonicalize() {
         Ok(path) => path,
@@ -916,7 +924,6 @@ fn open_with_access_check(
     } else {
       path
     };
-
     (*access_check)(true, &path, &options)?;
 
     // For windows
diff --git a/runtime/permissions/lib.rs b/runtime/permissions/lib.rs
index e66f16a7f..70d1abae7 100644
--- a/runtime/permissions/lib.rs
+++ b/runtime/permissions/lib.rs
@@ -1696,6 +1696,12 @@ impl PermissionsContainer {
         self.check_was_allow_all_flag_passed().map_err(error_all)?;
       }
     } else if cfg!(target_os = "windows") {
+      // \\.\nul is allowed
+      let s = path.as_os_str().as_encoded_bytes();
+      if s.eq_ignore_ascii_case(br#"\\.\nul"#) {
+        return Ok(());
+      }
+
       fn is_normalized_windows_drive_path(path: &Path) -> bool {
         let s = path.as_os_str().as_encoded_bytes();
         // \\?\X:\
diff --git a/tests/specs/permission/special/main.js b/tests/specs/permission/special/main.js
index 53a7adc9e..59ec4f7b5 100644
--- a/tests/specs/permission/special/main.js
+++ b/tests/specs/permission/special/main.js
@@ -5,6 +5,7 @@ const testCases = [
   // Allowed, safe
   [["darwin", "linux"], null, "/dev/null"],
   [["darwin", "linux"], null, "/etc/passwd"],
+  [["windows"], null, "\\\\.\\nul"],
   // Denied, requires `--allow-all`
   [["darwin", "linux"], /PermissionDenied/, "/dev/ptmx"],
   [["linux"], /PermissionDenied/, "/proc/self/environ"],
@@ -40,6 +41,7 @@ for (const [oses, error, file] of testCases) {
         console.log(`Got an error (expected) for ${file}: ${e}`);
       } else {
         console.log(`*** Got an unexpected error for ${file}: ${e}`);
+        failed = true;
       }
     }
   }