sys/unix/process: Reset signal behavior before exec

Make sure that child processes don't get affected by libstd's desire to
ignore SIGPIPE, nor a third-party library's signal mask (which is needed
to use either a signal-handling thread correctly or to use signalfd /
kqueue correctly).

1 files changed, 39 insertions, 0 deletions

diff --git a/src/test/run-pass/process-sigpipe.rs b/src/test/run-pass/process-sigpipe.rs
new file mode 100644
index 00000000000..5bff4fa080a
--- /dev/null
+++ b/src/test/run-pass/process-sigpipe.rs
@@ -0,0 +1,39 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// ignore-android since the dynamic linker sets a SIGPIPE handler (to do
+// a crash report) so inheritance is moot on the entire platform
+
+// libstd ignores SIGPIPE, and other libraries may set signal masks.
+// Make sure that these behaviors don't get inherited to children
+// spawned via std::process, since they're needed for traditional UNIX
+// filter behavior. This test checks that `yes | head` terminates
+// (instead of running forever), and that it does not print an error
+// message about a broken pipe.
+
+use std::process;
+use std::thread;
+
+#[cfg(unix)]
+fn main() {
+    // Just in case `yes` doesn't check for EPIPE...
+    thread::spawn(|| {
+        thread::sleep_ms(5000);
+        process::exit(1);
+    });
+    let output = process::Command::new("sh").arg("-c").arg("yes | head").output().unwrap();
+    assert!(output.status.success());
+    assert!(output.stderr.len() == 0);
+}
+
+#[cfg(not(unix))]
+fn main() {
+    // Not worried about signal masks on other platforms
+}