chown: fix --reference file syntax

src/uu/chown/src/chown.rs

@@ -131,8 +131,7 @@ pub fn uu_app() -> Command {
                 .long(options::REFERENCE)
                 .help(translate!("chown-help-reference"))
                 .value_name("RFILE")
-                .value_hint(clap::ValueHint::FilePath)
-                .num_args(1..),
+                .value_hint(clap::ValueHint::FilePath),
         )
         .arg(
             Arg::new(options::verbosity::SILENT)

tests/by-util/test_chown.rs

@@ -6,9 +6,9 @@
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use uucore::process::geteuid;
-use uutests::new_ucmd;
 use uutests::util::{CmdResult, TestScenario, is_ci, run_ucmd_as_root};
 use uutests::util_name;
+use uutests::{at_and_ucmd, new_ucmd};
 // Apparently some CI environments have configuration issues, e.g. with 'whoami' and 'id'.
 // If we are running inside the CI and "needle" is in "stderr" skipping this test is
 // considered okay. If we are not inside the CI this calls assert!(result.success).
@@ -844,3 +844,17 @@ fn test_chown_no_change_to_user_group() {
             ));
     }
 }
+
+#[test]
+fn test_chown_reference_file() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    at.touch("a");
+    at.touch("b");
+    ucmd.arg("--verbose")
+        .arg("--reference")
+        .arg("a")
+        .arg("b")
+        .succeeds()
+        .stderr_contains("ownership of 'b' retained as")
+        .no_stdout();
+}