ls: prevent ReadDir from closing before entries are processed

src/uu/ls/src/ls.rs

@@ -2305,7 +2305,7 @@ fn should_display(entry: &DirEntry, config: &Config) -> bool {
 #[allow(clippy::cognitive_complexity)]
 fn enter_directory(
     path_data: &PathData,
-    read_dir: ReadDir,
+    mut read_dir: ReadDir,
     config: &Config,
     state: &mut ListState,
     listed_ancestors: &mut HashSet<FileInformation>,
@@ -2334,7 +2334,7 @@ fn enter_directory(
     };
 
     // Convert those entries to the PathData struct
-    for raw_entry in read_dir {
+    for raw_entry in read_dir.by_ref() {
         let dir_entry = match raw_entry {
             Ok(path) => path,
             Err(err) => {

tests/by-util/test_ls.rs

@@ -6663,3 +6663,18 @@ fn test_f_with_long_format() {
     // Long format should still work (contains permissions, etc.)
     assert!(result.contains("-rw"));
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_ls_proc_self_fd_no_errors() {
+    // Regression test: ReadDir must stay alive until metadata() is called
+    // to prevent "cannot access '/proc/self/fd/3'" errors.
+    let scene = TestScenario::new(util_name!());
+
+    scene
+        .ucmd()
+        .arg("-l")
+        .arg("/proc/self/fd")
+        .succeeds()
+        .stderr_does_not_contain("cannot access");
+}