hashsum: Allow --text --tag

src/uu/hashsum/src/hashsum.rs

@@ -169,6 +169,15 @@ pub fn uumain(mut args: impl uucore::Args) -> UResult<()> {
         .unwrap()
         .map(|s| s.as_os_str());
 
+    // clap's conflicts_with does each other. So we manually rejects --tag --text while we do --text --tag by clap.
+    // cksum can do it naturally by clap via --untagged dep with correct message.
+    if matches.get_flag(options::TEXT) && std::env::args().any(|x| x == "--tag") {
+        return Err(uucore::error::UUsageError::new(
+            1,
+            "--tag --text is not allowed while --text --tag works (unrecommended)".to_string(),
+        ));
+    }
+
     if check {
         // No reason to allow --check with --binary/--text on Cygwin. It want to be same with Linux and --text was broken for a long time.
         let verbose = ChecksumVerbose::new(status, quiet, warn);
@@ -262,7 +271,7 @@ pub fn uu_app_common() -> Command {
                 .long("tag")
                 .help(translate!("hashsum-help-tag"))
                 .action(ArgAction::SetTrue)
-                .conflicts_with("text"),
+                .overrides_with(options::TEXT),
         )
         .arg(
             Arg::new(options::TEXT)

tests/by-util/test_hashsum.rs

@@ -606,6 +606,19 @@ fn test_conflicting_arg() {
         .fails_with_code(1);
 }
 
+#[cfg(target_os = "linux")]
+#[test]
+fn test_text_tag_device() {
+    let scene = TestScenario::new(util_name!());
+
+    scene
+        .ccmd("md5sum")
+        .arg("--text")
+        .arg("--tag")
+        .arg("/dev/null")
+        .succeeds();
+}
+
 #[test]
 fn test_tag() {
     let scene = TestScenario::new(util_name!());