id: Fix incorrect human-readable output (#7814)

Co-authored-by: Sylvestre Ledru <sylvestre@debian.org>

src/uu/id/locales/en-US.ftl

@@ -48,4 +48,5 @@ id-output-uid = uid
 id-output-groups = groups
 id-output-login = login
 id-output-euid = euid
+id-output-rgid = rgid
 id-output-context = context

src/uu/id/locales/fr-FR.ftl

@@ -48,4 +48,5 @@ id-output-uid = uid
 id-output-groups = groupes
 id-output-login = connexion
 id-output-euid = euid
+id-output-rgid = rgid
 id-output-context = contexte

src/uu/id/src/id.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (ToDO) asid auditid auditinfo auid cstr egid emod euid getaudit getlogin gflag nflag pline rflag termid uflag gsflag zflag cflag
+// spell-checker:ignore (ToDO) asid auditid auditinfo auid cstr egid rgid emod euid getaudit getlogin gflag nflag pline rflag termid uflag gsflag zflag cflag
 
 // README:
 // This was originally based on BSD's `id`
@@ -474,31 +474,32 @@ fn pretty(possible_pw: Option<Passwd>) {
         );
     } else {
         let login = cstr2cow!(getlogin().cast_const());
-        let rid = getuid();
-        if let Ok(p) = Passwd::locate(rid) {
+        let uid = getuid();
+        if let Ok(p) = Passwd::locate(uid) {
             if let Some(user_name) = login {
                 println!("{}\t{user_name}", translate!("id-output-login"));
             }
             println!("{}\t{}", translate!("id-output-uid"), p.name);
         } else {
-            println!("{}\t{rid}", translate!("id-output-uid"));
+            println!("{}\t{uid}", translate!("id-output-uid"));
         }
 
-        let eid = getegid();
-        if eid == rid {
-            if let Ok(p) = Passwd::locate(eid) {
+        let euid = geteuid();
+        if euid != uid {
+            if let Ok(p) = Passwd::locate(euid) {
                 println!("{}\t{}", translate!("id-output-euid"), p.name);
             } else {
-                println!("{}\t{eid}", translate!("id-output-euid"));
+                println!("{}\t{euid}", translate!("id-output-euid"));
             }
         }
 
-        let rid = getgid();
-        if rid != eid {
-            if let Ok(g) = Group::locate(rid) {
-                println!("{}\t{}", translate!("id-output-euid"), g.name);
+        let rgid = getgid();
+        let egid = getegid();
+        if egid != rgid {
+            if let Ok(g) = Group::locate(rgid) {
+                println!("{}\t{}", translate!("id-output-rgid"), g.name);
             } else {
-                println!("{}\t{rid}", translate!("id-output-euid"));
+                println!("{}\t{rgid}", translate!("id-output-rgid"));
             }
         }
 

tests/by-util/test_id.rs

@@ -3,7 +3,7 @@
 // For the full copyright and license information, please view the LICENSE
 // file that was distributed with this source code.
 
-// spell-checker:ignore (ToDO) coreutil
+// spell-checker:ignore (ToDO) coreutil euid rgid
 
 use std::process::{Command, Stdio};
 use uutests::new_ucmd;
@@ -11,6 +11,9 @@ use uutests::unwrap_or_return;
 use uutests::util::{TestScenario, check_coreutil_version, expected_result, is_ci, whoami};
 use uutests::util_name;
 
+#[cfg(all(feature = "chmod", feature = "chown"))]
+use tempfile::TempPath;
+
 const VERSION_MIN_MULTIPLE_USERS: &str = "8.31"; // this feature was introduced in GNU's coreutils 8.31
 
 #[test]
@@ -477,6 +480,55 @@ fn test_id_pretty_print_password_record() {
         .stderr_contains("the argument '-p' cannot be used with '-P'");
 }
 
+#[test]
+#[cfg(all(feature = "chmod", feature = "chown"))]
+fn test_id_pretty_print_suid_binary() {
+    use uucore::process::{getgid, getuid};
+
+    if let Some(suid_coreutils_path) = create_root_owned_suid_coreutils_binary() {
+        let result = TestScenario::new(util_name!())
+            .cmd(suid_coreutils_path.to_str().unwrap())
+            .args(&[util_name!(), "-p"])
+            .succeeds();
+
+        // The `euid` line should be present only if the real UID does not belong to `root`
+        if getuid() == 0 {
+            result.stdout_does_not_contain("euid\t");
+        } else {
+            result.stdout_contains_line("euid\troot");
+        }
+
+        // The `rgid` line should be present only if the real GID does not belong to `root`
+        if getgid() == 0 {
+            result.stdout_does_not_contain("rgid\t");
+        } else {
+            result.stdout_contains("rgid\t");
+        }
+    } else {
+        print!("Test skipped; requires root user");
+    }
+}
+
+/// Create SUID temp file owned by `root:root` with the contents of the `coreutils` binary
+#[cfg(all(feature = "chmod", feature = "chown"))]
+fn create_root_owned_suid_coreutils_binary() -> Option<TempPath> {
+    use std::fs::read;
+    use std::io::Write;
+    use tempfile::NamedTempFile;
+    use uutests::util::{get_tests_binary, run_ucmd_as_root};
+
+    let mut temp_file = NamedTempFile::new().unwrap();
+    let coreutils_binary = read(get_tests_binary()).unwrap();
+    temp_file.write_all(&coreutils_binary).unwrap();
+    let temp_path = temp_file.into_temp_path();
+    let temp_path_str = temp_path.to_str().unwrap();
+
+    run_ucmd_as_root(&TestScenario::new("chown"), &["root:root", temp_path_str]).ok()?;
+    run_ucmd_as_root(&TestScenario::new("chmod"), &["+xs", temp_path_str]).ok()?;
+
+    Some(temp_path)
+}
+
 /// This test requires user with username 200 on system
 #[test]
 #[cfg(unix)]