chmod: preserve metadata errors for overlong paths

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

@@ -4,7 +4,6 @@ chmod-usage = chmod [OPTION]... MODE[,MODE]... FILE...
   chmod [OPTION]... OCTAL-MODE FILE...
   chmod [OPTION]... --reference=RFILE FILE...
 chmod-after-help = Each MODE is of the form [ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=]?[0-7]+.
-chmod-error-cannot-stat = cannot stat attributes of {$file}
 chmod-error-dangling-symlink = cannot operate on dangling symlink {$file}
 chmod-error-no-such-file = cannot access {$file}: No such file or directory
 chmod-error-preserve-root = it is dangerous to operate recursively on {$file}
@@ -15,6 +14,7 @@ chmod-error-permission-denied = cannot access {$file}: Permission denied
 chmod-error-new-permissions = {$file}: new permissions are {$actual}, not {$expected}
 chmod-error-changing-permissions = changing permissions of {$file}: {$err}
 chmod-error-missing-operand = missing operand
+chmod-error-reference-stat = failed to get attributes of { $file }: { $error }
 
 # Help messages
 chmod-help-print-help = Print help information.

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

@@ -16,7 +16,6 @@ chmod-help-recursive = changer les fichiers et répertoires récursivement
 chmod-help-reference = utiliser le mode de RFICHIER au lieu des valeurs de MODE
 
 # Messages d'erreur
-chmod-error-cannot-stat = impossible d'obtenir les attributs de {$file}
 chmod-error-dangling-symlink = impossible d'opérer sur le lien symbolique pendouillant {$file}
 chmod-error-no-such-file = impossible d'accéder à {$file} : Aucun fichier ou répertoire de ce type
 chmod-error-preserve-root = il est dangereux d'opérer récursivement sur {$file}
@@ -27,6 +26,7 @@ chmod-error-permission-denied = impossible d'accéder à {$file} : Permission re
 chmod-error-new-permissions = {$file} : les nouvelles permissions sont {$actual}, pas {$expected}
 chmod-error-changing-permissions = changement des permissions de {$file} : {$err}
 chmod-error-missing-operand = opérande manquant
+chmod-error-reference-stat = impossible d'obtenir les attributs de { $file } : { $error }
 
 # Messages verbeux/de statut
 chmod-verbose-failed-dangling = échec du changement de mode de {$file} de 0000 (---------) vers 1500 (r-x-----T)

src/uu/chmod/src/chmod.rs

@@ -29,8 +29,10 @@ use uucore::translate;
 
 #[derive(Debug, thiserror::Error)]
 enum ChmodError {
-    #[error("{}", translate!("chmod-error-cannot-stat", "file" => _0.quote()))]
-    CannotStat(PathBuf),
+    #[error("{}", translate!("perms-cannot-access", "file" => _0.quote(), "error" => strip_errno(_1)))]
+    CannotStat(PathBuf, std::io::Error),
+    #[error("{}", translate!("chmod-error-reference-stat", "file" => _0.quote(), "error" => strip_errno(_1)))]
+    ReferenceStat(PathBuf, std::io::Error),
     #[error("{}", translate!("chmod-error-dangling-symlink", "file" => _0.quote()))]
     DanglingSymlink(PathBuf),
     #[error("{}", translate!("chmod-error-no-such-file", "file" => _0.quote()))]
@@ -150,7 +152,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         Some(fref) => Some(
             fs::metadata(fref)
                 .map(|meta| meta.mode() & 0o7777)
-                .map_err(|_| ChmodError::CannotStat(fref.into()))?,
+                .map_err(|err| ChmodError::ReferenceStat(fref.into(), err))?,
         ),
         None => None,
     };
@@ -817,7 +819,7 @@ impl Chmoder {
                 } else if err.kind() == std::io::ErrorKind::PermissionDenied {
                     Err(ChmodError::PermissionDenied(file.into()).into())
                 } else {
-                    Err(ChmodError::CannotStat(file.into()).into())
+                    Err(ChmodError::CannotStat(file.into(), err).into())
                 };
             }
         };

tests/by-util/test_chmod.rs

@@ -1865,3 +1865,35 @@
             .no_output();
     }
 }
+
+#[test]
+fn test_overlong_path_reports_os_error_and_continues() {
+    let ts = TestScenario::new(util_name!());
+    ts.fixtures.touch("valid");
+    // Every component exists, but the unnormalized operand exceeds PATH_MAX.
+    let path = "./".repeat(4096);
+    let error = uucore::error::strip_errno(&std::io::Error::from_raw_os_error(libc::ENAMETOOLONG));
+    for flags in [vec![], vec!["-R"]] {
+        set_permissions(ts.fixtures.plus("valid"), Permissions::from_mode(0o600)).unwrap();
+        let result = ts
+            .ucmd()
+            .args(&flags)
+            .arg("700")
+            .arg(&path)
+            .arg("valid")
+            .fails_with_code(1);
+        result.stderr_is(format!("chmod: cannot access '{path}': {error}\n"));
+        assert_eq!(
+            ts.fixtures.metadata("valid").permissions().mode() & 0o777,
+            0o700
+        );
+    }
+    ts.ucmd()
+        .arg("--reference")
+        .arg(&path)
+        .arg("valid")
+        .fails_with_code(1)
+        .stderr_is(format!(
+            "chmod: failed to get attributes of '{path}': {error}\n"
+        ));
+}