Add another test for hardlinks to symlinks.

tests/fs_additional.rs

@@ -403,6 +403,67 @@ fn dir_searchable_unreadable() {
         .is_err());
 }
 
+/// This test is the same as `symlink_hard_link` but uses `std::fs`'
+/// ambient API instead of `cap_std`. The purpose of this test is to
+/// confirm fundamentally OS-specific behaviors.
+#[test]
+#[cfg_attr(any(target_os = "macos", target_os = "freebsd"), ignore)] // submitted to upstream as https://github.com/rust-lang/rust/pull/78026
+fn symlink_hard_link_ambient() {
+    #[cfg(unix)]
+    use std::os::unix::fs::symlink;
+    #[cfg(windows)]
+    use std::os::windows::fs::symlink_file;
+
+    let dir = tempfile::tempdir().unwrap();
+
+    check!(std::fs::File::create(dir.path().join("file")));
+    #[cfg(not(windows))]
+    check!(symlink("file", dir.path().join("symlink")));
+    #[cfg(windows)]
+    check!(symlink_file("file", dir.path().join("symlink")));
+    check!(std::fs::hard_link(
+        dir.path().join("symlink"),
+        dir.path().join("hard_link")
+    ));
+    assert!(
+        check!(std::fs::symlink_metadata(dir.path().join("hard_link")))
+            .file_type()
+            .is_symlink()
+    );
+    let _ = check!(std::fs::File::open(dir.path().join("file")));
+    assert!(std::fs::File::open(dir.path().join("file.renamed")).is_err());
+    let _ = check!(std::fs::File::open(dir.path().join("symlink")));
+    let _ = check!(std::fs::File::open(dir.path().join("hard_link")));
+    check!(std::fs::rename(
+        dir.path().join("file"),
+        dir.path().join("file.renamed")
+    ));
+    assert!(std::fs::File::open(dir.path().join("file")).is_err());
+    let _ = check!(std::fs::File::open(dir.path().join("file.renamed")));
+    assert!(std::fs::File::open(dir.path().join("symlink")).is_err());
+    assert!(std::fs::File::open(dir.path().join("hard_link")).is_err());
+    assert!(std::fs::read_link(dir.path().join("file")).is_err());
+    assert!(std::fs::read_link(dir.path().join("file.renamed")).is_err());
+    assert_eq!(
+        check!(std::fs::read_link(dir.path().join("symlink"))),
+        Path::new("file")
+    );
+    assert_eq!(
+        check!(std::fs::read_link(dir.path().join("hard_link"))),
+        Path::new("file")
+    );
+    check!(std::fs::remove_file(dir.path().join("file.renamed")));
+    assert!(std::fs::File::open(dir.path().join("file")).is_err());
+    assert!(std::fs::File::open(dir.path().join("file.renamed")).is_err());
+    assert!(std::fs::File::open(dir.path().join("symlink")).is_err());
+    assert!(std::fs::File::open(dir.path().join("hard_link")).is_err());
+    assert!(
+        check!(std::fs::symlink_metadata(dir.path().join("hard_link")))
+            .file_type()
+            .is_symlink()
+    );
+}
+
 /// POSIX says that whether or not `link` follows symlinks in the `old`
 /// path is implementation-defined. We want `hard_link` to not follow
 /// symbolic links.
@@ -413,7 +474,28 @@ fn symlink_hard_link() {
     check!(tmpdir.create("file"));
     check!(symlink_file("file", &tmpdir, "symlink"));
     check!(tmpdir.hard_link("symlink", &tmpdir, "hard_link"));
+    assert!(check!(tmpdir.symlink_metadata("hard_link"))
+        .file_type()
+        .is_symlink());
+    let _ = check!(tmpdir.open("file"));
+    assert!(tmpdir.open("file.renamed").is_err());
+    let _ = check!(tmpdir.open("symlink"));
     let _ = check!(tmpdir.open("hard_link"));
     check!(tmpdir.rename("file", &tmpdir, "file.renamed"));
+    assert!(tmpdir.open("file").is_err());
+    let _ = check!(tmpdir.open("file.renamed"));
+    assert!(tmpdir.open("symlink").is_err());
+    assert!(tmpdir.open("hard_link").is_err());
+    assert!(tmpdir.read_link("file").is_err());
+    assert!(tmpdir.read_link("file.renamed").is_err());
+    assert_eq!(check!(tmpdir.read_link("symlink")), Path::new("file"));
+    assert_eq!(check!(tmpdir.read_link("hard_link")), Path::new("file"));
+    check!(tmpdir.remove_file("file.renamed"));
+    assert!(tmpdir.open("file").is_err());
+    assert!(tmpdir.open("file.renamed").is_err());
+    assert!(tmpdir.open("symlink").is_err());
     assert!(tmpdir.open("hard_link").is_err());
+    assert!(check!(tmpdir.symlink_metadata("hard_link"))
+        .file_type()
+        .is_symlink());
 }