Windows: Use `FindFirstFileW` if `metadata` fails

Usually opening a file handle with access set to metadata only will always succeed, even if the file is locked. However some special system files, such as `C:\hiberfil.sys`, are locked by the system in a way that denies even that. So as a fallback we try reading the cached metadata from the directory.

1 files changed, 11 insertions, 0 deletions

diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs
index e8d0132f4b9..e1ebb1a690b 100644
--- a/library/std/src/fs/tests.rs
+++ b/library/std/src/fs/tests.rs
@@ -1534,3 +1534,14 @@ fn read_large_dir() {
         entry.unwrap();
     }
 }
+
+#[test]
+#[cfg(windows)]
+fn hiberfil_sys() {
+    // Get the system drive, which is usually `C:`.
+    let mut hiberfil = crate::env::var("SystemDrive").unwrap();
+    hiberfil.push_str(r"\hiberfil.sys");
+
+    fs::metadata(&hiberfil).unwrap();
+    fs::symlink_metadata(&hiberfil).unwrap();
+}