truncate: reject a size above i64::MAX instead of creating the file

src/uu/truncate/src/truncate.rs

@@ -279,6 +279,21 @@ fn file_truncate(
             }
         })?;
 
+    // A size above i64::MAX is not a valid file offset; reject it up front like
+    // GNU, instead of creating the file and failing when it is opened.
+    if truncate_size > i64::MAX as u64 {
+        let error = match size_argument {
+            None => translate!("truncate-error-value-too-large"),
+            Some(arg) => {
+                translate!("truncate-error-value-too-large-arg", "arg" => arg.quote())
+            }
+        };
+        return Err(USimpleError::new(
+            1,
+            translate!("truncate-error-invalid-number", "error" => error),
+        ));
+    }
+
     do_file_truncate(path, !no_create, truncate_size)
 }
 

tests/by-util/test_truncate.rs

@@ -38,6 +38,16 @@ fn test_increase_file_size_kb() {
     assert_eq!(expected, actual, "expected '{expected}' got '{actual}'");
 }
 
+#[test]
+fn test_size_above_i64_max_is_rejected_without_creating_file() {
+    // A size above i64::MAX is rejected up front and the file is not created.
+    let (at, mut ucmd) = at_and_ucmd!();
+    ucmd.args(&["-s", "9223372036854775808", "new-file"])
+        .fails_with_code(1)
+        .stderr_contains("Value too large for defined data type");
+    assert!(!at.file_exists("new-file"));
+}
+
 #[test]
 fn test_reference() {
     let expected = 5 * 1000;