From eefdeacdb1aa2515359ba3cedfb04c81d74e783a Mon Sep 17 00:00:00 2001
From: Ben Kimock <kimockb@gmail.com>
Date: Sun, 17 Jul 2022 21:13:59 -0400
Subject: [PATCH] Test that isatty doesn't crash

---
 tests/pass/libc.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tests/pass/libc.rs b/tests/pass/libc.rs
index 53c85d2b07d1..6da527927071 100644
--- a/tests/pass/libc.rs
+++ b/tests/pass/libc.rs
@@ -311,6 +311,17 @@ fn test_posix_gettimeofday() {
     assert_eq!(is_error, -1);
 }
 
+fn test_isatty() {
+    // Testing whether our isatty shim returns the right value would require controlling whether
+    // these streams are actually TTYs, which is hard.
+    // For now, we just check that these calls are supported at all.
+    unsafe {
+        libc::isatty(libc::STDIN_FILENO);
+        libc::isatty(libc::STDOUT_FILENO);
+        libc::isatty(libc::STDERR_FILENO);
+    }
+}
+
 fn main() {
     #[cfg(any(target_os = "linux", target_os = "freebsd"))]
     test_posix_fadvise();
@@ -335,4 +346,6 @@ fn main() {
 
     #[cfg(any(target_os = "linux"))]
     test_clocks();
+
+    test_isatty();
 }