From 68e777d9fd7eb56879756ebbddd1ae914dbd968a Mon Sep 17 00:00:00 2001
From: naoNao89 <90588855+naoNao89@users.noreply.github.com>
Date: Wed, 6 May 2026 11:01:41 +0700
Subject: [PATCH] test(cksum): regression test for write errors to /dev/full

Adds a Linux-only regression test that verifies cksum exits with
code 1 (rather than panicking) when stdout is /dev/full.

Refs #10947 (fixed by #12099).
---
 tests/by-util/test_cksum.rs | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tests/by-util/test_cksum.rs b/tests/by-util/test_cksum.rs
index 7998ae13d8f..3a208fb1943 100644
--- a/tests/by-util/test_cksum.rs
+++ b/tests/by-util/test_cksum.rs
@@ -3423,3 +3423,20 @@ fn test_check_blake3_untagged(
         .succeeds()
         .stdout_only("FILE: OK\n");
 }
+
+// Regression test: cksum should handle write errors to /dev/full without aborting.
+#[test]
+#[cfg(target_os = "linux")]
+fn test_write_error_dev_full() {
+    use std::fs::OpenOptions;
+    let dev_full = OpenOptions::new()
+        .write(true)
+        .open("/dev/full")
+        .expect("Failed to open /dev/full - test must run on Linux");
+
+    new_ucmd!()
+        .arg("/dev/null")
+        .set_stdout(dev_full)
+        .fails()
+        .code_is(1);
+}