fix tr with delete flag if more than 1 operand given (#5945)

* fix tr

* fix

* adding a test

* tr: rename test function

---------

Co-authored-by: Daniel Hofstetter <daniel.hofstetter@42dh.com>

src/uu/tr/src/tr.rs

@@ -61,6 +61,13 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         ));
     }
 
+    if delete_flag && !squeeze_flag && sets_len > 1 {
+        return Err(UUsageError::new(
+            1,
+            format!("extra operand {}\nOnly one string may be given when deleting without squeezing repeats.", sets[1].quote()),
+        ));
+    }
+
     if let Some(first) = sets.first() {
         if first.ends_with('\\') {
             show!(USimpleError::new(

tests/by-util/test_tr.rs

@@ -1147,3 +1147,15 @@ fn check_against_gnu_tr_tests_no_abort_1() {
         .succeeds()
         .stdout_is("abb");
 }
+
+#[test]
+fn test_delete_flag_takes_only_one_operand() {
+    // gnu tr -d fails with more than 1 argument
+    new_ucmd!()
+        .args(&["-d", "a", "p"])
+        .pipe_in("abc")
+        .fails()
+        .stderr_contains(
+        "extra operand 'p'\nOnly one string may be given when deleting without squeezing repeats.",
+    );
+}