test_timeout: Add tests for very short timeouts

drinkcat · drinkcat · commit edc213d2c7f1 · 2025-04-04T18:23:17.000+02:00
Note that unlike GNU coreutils, any value &gt; 0 will not be treated
as 0, even if the exponent is very large.
diff --git a/tests/by-util/test_timeout.rs b/tests/by-util/test_timeout.rs
@@ -125,6 +125,24 @@ fn test_dont_overflow() {
         .no_output();
 }
 
+#[test]
+fn test_dont_underflow() {
+    new_ucmd!()
+        .args(&[".0000000001", "sleep", "1"])
+        .fails_with_code(124)
+        .no_output();
+    new_ucmd!()
+        .args(&["1e-100", "sleep", "1"])
+        .fails_with_code(124)
+        .no_output();
+    // Unlike GNU coreutils, we underflow to 1ns for very short timeouts.
+    // https://debbugs.gnu.org/cgi/bugreport.cgi?bug=77535
+    new_ucmd!()
+        .args(&["1e-18172487393827593258", "sleep", "1"])
+        .fails_with_code(124)
+        .no_output();
+}
+
 #[test]
 fn test_negative_interval() {
     new_ucmd!()
