truncate: don't error in --no-create with reference case

src/uu/truncate/src/truncate.rs

@@ -180,8 +180,11 @@ pub fn uu_app() -> Command {
 /// size of the file.
 fn file_truncate(filename: &str, create: bool, size: u64) -> std::io::Result<()> {
     let path = Path::new(filename);
-    let f = OpenOptions::new().write(true).create(create).open(path)?;
-    f.set_len(size)
+    match OpenOptions::new().write(true).create(create).open(path) {
+        Ok(file) => file.set_len(size),
+        Err(e) if e.kind() == ErrorKind::NotFound && !create => Ok(()),
+        Err(e) => Err(e),
+    }
 }
 
 /// Truncate files to a size relative to a given file.
@@ -337,15 +340,8 @@ fn truncate_size_only(size_string: &str, filenames: &[String], create: bool) ->
             Err(_) => 0,
         };
         let tsize = mode.to_size(fsize);
-        match file_truncate(filename, create, tsize) {
-            Ok(_) => continue,
-            Err(e) if e.kind() == ErrorKind::NotFound && !create => continue,
-            Err(e) => {
-                return Err(
-                    e.map_err_context(|| format!("cannot open {} for writing", filename.quote()))
-                )
-            }
-        }
+        file_truncate(filename, create, tsize)
+            .map_err_context(|| format!("cannot open {} for writing", filename.quote()))?;
     }
     Ok(())
 }

tests/by-util/test_truncate.rs

@@ -268,7 +268,7 @@ fn test_new_file() {
 
 /// Test for not creating a non-existent file.
 #[test]
-fn test_new_file_no_create() {
+fn test_new_file_no_create_size_only() {
     let (at, mut ucmd) = at_and_ucmd!();
     let filename = "new_file_that_does_not_exist_yet";
     ucmd.args(&["-s", "8", "-c", filename])
@@ -278,6 +278,36 @@ fn test_new_file_no_create() {
     assert!(!at.file_exists(filename));
 }
 
+/// Test for not creating a non-existent file.
+#[test]
+#[ignore = "other bug"]
+fn test_new_file_no_create_reference_only() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let mut old_file = at.make_file(FILE1);
+    old_file.write_all(b"1234567890").unwrap();
+    let filename = "new_file_that_does_not_exist_yet";
+    ucmd.args(&["-r", FILE1, "-c", filename])
+        .succeeds()
+        .no_stdout()
+        .no_stderr();
+    assert!(!at.file_exists(filename));
+}
+
+/// Test for not creating a non-existent file.
+#[test]
+#[ignore = "other bug"]
+fn test_new_file_no_create_size_and_reference() {
+    let (at, mut ucmd) = at_and_ucmd!();
+    let mut old_file = at.make_file(FILE1);
+    old_file.write_all(b"1234567890").unwrap();
+    let filename = "new_file_that_does_not_exist_yet";
+    ucmd.args(&["-r", FILE1, "-s", "+8", "-c", filename])
+        .succeeds()
+        .no_stdout()
+        .no_stderr();
+    assert!(!at.file_exists(filename));
+}
+
 #[test]
 fn test_division_by_zero_size_only() {
     new_ucmd!()