Revert 00bf74da6d1e8e49b18c0203e0cbd993fdac5663

library/std/src/fs.rs

@@ -2446,14 +2446,12 @@ pub fn symlink_metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `rename` function on Unix
-/// and the `SetFileInformationByHandle` function on Windows.
+/// and the `MoveFileEx` function with the `MOVEFILE_REPLACE_EXISTING` flag on Windows.
 ///
 /// Because of this, the behavior when both `from` and `to` exist differs. On
 /// Unix, if `from` is a directory, `to` must also be an (empty) directory. If
-/// `from` is not a directory, `to` must also be not a directory. The behavior
-/// on Windows is the same on Windows 10 1607 and higher if `FileRenameInfoEx`
-/// is supported by the filesystem; otherwise, `from` can be anything, but
-/// `to` must *not* be a directory.
+/// `from` is not a directory, `to` must also be not a directory. In contrast,
+/// on Windows, `from` can be anything, but `to` must *not* be a directory.
 ///
 /// Note that, this [may change in the future][changes].
 ///

library/std/src/fs/tests.rs

@@ -1913,77 +1913,3 @@ fn test_hidden_file_truncation() {
     let metadata = file.metadata().unwrap();
     assert_eq!(metadata.len(), 0);
 }
-
-// See https://github.com/rust-lang/rust/pull/131072 for more details about why
-// these two tests are disabled under Windows 7 here.
-#[cfg(windows)]
-#[test]
-#[cfg_attr(target_vendor = "win7", ignore = "Unsupported under Windows 7.")]
-fn test_rename_file_over_open_file() {
-    // Make sure that std::fs::rename works if the target file is already opened with FILE_SHARE_DELETE. See #123985.
-    let tmpdir = tmpdir();
-
-    // Create source with test data to read.
-    let source_path = tmpdir.join("source_file.txt");
-    fs::write(&source_path, b"source hello world").unwrap();
-
-    // Create target file with test data to read;
-    let target_path = tmpdir.join("target_file.txt");
-    fs::write(&target_path, b"target hello world").unwrap();
-
-    // Open target file
-    let target_file = fs::File::open(&target_path).unwrap();
-
-    // Rename source
-    fs::rename(source_path, &target_path).unwrap();
-
-    core::mem::drop(target_file);
-    assert_eq!(fs::read(target_path).unwrap(), b"source hello world");
-}
-
-#[test]
-#[cfg(windows)]
-#[cfg_attr(target_vendor = "win7", ignore = "Unsupported under Windows 7.")]
-fn test_rename_directory_to_non_empty_directory() {
-    // Renaming a directory over a non-empty existing directory should fail on Windows.
-    let tmpdir: TempDir = tmpdir();
-
-    let source_path = tmpdir.join("source_directory");
-    let target_path = tmpdir.join("target_directory");
-
-    fs::create_dir(&source_path).unwrap();
-    fs::create_dir(&target_path).unwrap();
-
-    fs::write(target_path.join("target_file.txt"), b"target hello world").unwrap();
-
-    error!(fs::rename(source_path, target_path), 145); // ERROR_DIR_NOT_EMPTY
-}
-
-#[test]
-fn test_rename_symlink() {
-    let tmpdir = tmpdir();
-    let original = tmpdir.join("original");
-    let dest = tmpdir.join("dest");
-    let not_exist = Path::new("does not exist");
-
-    symlink_file(not_exist, &original).unwrap();
-    fs::rename(&original, &dest).unwrap();
-    // Make sure that renaming `original` to `dest` preserves the symlink.
-    assert_eq!(fs::read_link(&dest).unwrap().as_path(), not_exist);
-}
-
-#[test]
-#[cfg(windows)]
-fn test_rename_junction() {
-    let tmpdir = tmpdir();
-    let original = tmpdir.join("original");
-    let dest = tmpdir.join("dest");
-    let not_exist = Path::new("does not exist");
-
-    junction_point(&not_exist, &original).unwrap();
-    fs::rename(&original, &dest).unwrap();
-
-    // Make sure that renaming `original` to `dest` preserves the junction point.
-    // Junction links are always absolute so we just check the file name is correct.
-    assert_eq!(fs::read_link(&dest).unwrap().file_name(), Some(not_exist.as_os_str()));
-}

library/std/src/lib.rs

@@ -174,7 +174,9 @@
 //!
 //! - after-main use of thread-locals, which also affects additional features:
 //!   - [`thread::current()`]
-//! - before-main stdio file descriptors are not guaranteed to be open on unix platforms
+//! - under UNIX, before main, file descriptors 0, 1, and 2 may be unchanged
+//!   (they are guaranteed to be open during main,
+//!    and are opened to /dev/null O_RDWR if they weren't open on program start)
 //!
 //!
 //! [I/O]: io