Merge pull request #4928 from granquet/cp_preserve

cp: makes --preserve requires =

src/uu/cp/src/cp.rs

@@ -515,6 +515,7 @@ pub fn uu_app() -> Command {
                     PRESERVABLE_ATTRIBUTES,
                 ))
                 .num_args(0..)
+                .require_equals(true)
                 .value_name("ATTR_LIST")
                 .overrides_with_all([
                     options::ARCHIVE,

tests/by-util/test_cp.rs

@@ -1223,6 +1223,33 @@ fn test_cp_preserve_no_args() {
     }
 }
 
+#[test]
+fn test_cp_preserve_no_args_before_opts() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let src_file = "a";
+    let dst_file = "b";
+
+    // Prepare the source file
+    at.touch(src_file);
+    #[cfg(unix)]
+    at.set_mode(src_file, 0o0500);
+
+    // Copy
+    ucmd.arg("--preserve")
+        .arg(src_file)
+        .arg(dst_file)
+        .succeeds();
+
+    #[cfg(all(unix, not(target_os = "freebsd")))]
+    {
+        // Assert that the mode, ownership, and timestamps are preserved
+        // NOTICE: the ownership is not modified on the src file, because that requires root permissions
+        let metadata_src = at.metadata(src_file);
+        let metadata_dst = at.metadata(dst_file);
+        assert_metadata_eq!(metadata_src, metadata_dst);
+    }
+}
+
 #[test]
 fn test_cp_preserve_all() {
     let (at, mut ucmd) = at_and_ucmd!();