date, comm, tty: Fixing handling output to dev/null

src/uu/comm/src/comm.rs

@@ -310,7 +310,9 @@ fn comm(
         .map_err_context(|| translate!("comm-error-write"))?;
     }
 
-    writer.flush().ok();
+    writer
+        .flush()
+        .map_err_context(|| translate!("comm-error-write"))?;
 
     if should_check_order && (checker1.has_error || checker2.has_error) {
         // Print the input error message once at the end

src/uu/date/src/date.rs

@@ -510,6 +510,9 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         }
     }
 
+    stdout
+        .flush()
+        .map_err(|e| USimpleError::new(1, translate!("date-error-write", "error" => e)))?;
     Ok(())
 }
 

src/uu/tty/src/tty.rs

@@ -19,13 +19,13 @@ mod options {
 
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let matches = uucore::clap_localization::handle_clap_result_with_exit_code(uu_app(), args, 2)?;
+
     // Disable SIGPIPE so we can handle broken pipe errors gracefully
     // and exit with code 3 instead of being killed by the signal.
     #[cfg(unix)]
     let _ = uucore::signals::disable_pipe_errors();
 
-    let matches = uucore::clap_localization::handle_clap_result_with_exit_code(uu_app(), args, 2)?;
-
     let silent = matches.get_flag(options::SILENT);
 
     // If silent, we don't need the name, only whether or not stdin is a tty.

tests/by-util/test_comm.rs

@@ -727,3 +727,18 @@ fn test_read_error() {
         .fails()
         .stderr_contains("comm: /proc/self/mem: Input/output error");
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_comm_write_error_dev_full() {
+    use std::fs::OpenOptions;
+    let scene = TestScenario::new(util_name!());
+    scene.fixtures.write("a", "a\n");
+    let dev_full = OpenOptions::new().write(true).open("/dev/full").unwrap();
+    scene
+        .ucmd()
+        .args(&["a", "a"])
+        .set_stdout(dev_full)
+        .fails()
+        .stderr_contains("No space left on device");
+}

tests/by-util/test_date.rs

@@ -2066,3 +2066,15 @@ fn test_percent_percent_not_replaced() {
             .stdout_is(expected);
     }
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_date_write_error_dev_full() {
+    use std::fs::OpenOptions;
+    let dev_full = OpenOptions::new().write(true).open("/dev/full").unwrap();
+    new_ucmd!()
+        .arg("+%s")
+        .set_stdout(dev_full)
+        .fails()
+        .stderr_contains("write error");
+}

tests/by-util/test_tty.rs

@@ -87,3 +87,11 @@ fn test_stdout_fail() {
     let status = proc.wait().unwrap();
     assert_eq!(status.code(), Some(3));
 }
+
+#[test]
+#[cfg(unix)]
+fn test_version_pipe_no_stderr() {
+    let mut child = new_ucmd!().arg("--version").run_no_wait();
+    child.close_stdout();
+    child.wait().unwrap().no_stderr();
+}