fs: Copy file permissions (#2354)

Signed-off-by: Kevin Leimkuhler <[email protected]>

tokio/src/fs/copy.rs

@@ -1,5 +1,4 @@
-use crate::fs::File;
-use crate::io;
+use crate::fs::asyncify;
 use std::path::Path;
 
 /// Copies the contents of one file to another. This function will also copy the permission bits of the original file to the destination file.
@@ -19,8 +18,7 @@ use std::path::Path;
 /// ```
 
 pub async fn copy<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> Result<u64, std::io::Error> {
-    let from = File::open(from).await?;
-    let to = File::create(to).await?;
-    let (mut from, mut to) = (io::BufReader::new(from), io::BufWriter::new(to));
-    io::copy(&mut from, &mut to).await
+    let from = from.as_ref().to_owned();
+    let to = to.as_ref().to_owned();
+    asyncify(|| std::fs::copy(from, to)).await
 }

tokio/tests/fs_copy.rs

@@ -19,3 +19,21 @@ async fn copy() {
 
     assert_eq!(from, to);
 }
+
+#[tokio::test]
+async fn copy_permissions() {
+    let dir = tempdir().unwrap();
+    let from_path = dir.path().join("foo.txt");
+    let to_path = dir.path().join("bar.txt");
+
+    let from = tokio::fs::File::create(&from_path).await.unwrap();
+    let mut from_perms = from.metadata().await.unwrap().permissions();
+    from_perms.set_readonly(true);
+    from.set_permissions(from_perms.clone()).await.unwrap();
+
+    tokio::fs::copy(from_path, &to_path).await.unwrap();
+
+    let to_perms = tokio::fs::metadata(to_path).await.unwrap().permissions();
+
+    assert_eq!(from_perms, to_perms);
+}