T04: close the pty master before reaping, so a program ignoring SIGHUP ends

src/term/pty.rs

@@ -269,14 +269,11 @@ mod tests {
         assert_eq!(ran.text, format!("8 {}", u16::MAX / 8));
     }
 
-    #[test]
-    fn closing_a_session_hangs_up_its_program() {
+    /// Starts `script`, waits for it to print READY, closes it, and waits for the reap's log.
+    fn close_after_ready(script: &str, reaped: &str) {
         crate::testlog::init();
         let launch = Launch {
-            program: Some((
-                "/bin/sh".into(),
-                vec!["-c".into(), "printf READY; exec cat".into()],
-            )),
+            program: Some(("/bin/sh".into(), vec!["-c".into(), script.into()])),
             cwd: std::env::temp_dir(),
             env: Vec::new(),
         };
@@ -295,7 +292,7 @@ mod tests {
         });
         let pid = pty.pid;
         drop(pty);
-        let hung_up = format!("pty {pid}: hung up, signal: 1 (SIGHUP)");
+        let hung_up = format!("pty {pid}: hung up, {reaped}");
         let deadline = std::time::Instant::now() + std::time::Duration::from_secs(5);
         while !crate::testlog::logged(&hung_up) {
             assert!(std::time::Instant::now() < deadline, "no `{hung_up}`");
@@ -306,6 +303,16 @@ mod tests {
         assert!(!alive, "the program was reaped");
     }
 
+    #[test]
+    fn closing_a_session_hangs_up_its_program() {
+        close_after_ready("printf READY; exec cat", "signal: 1 (SIGHUP)");
+    }
+
+    #[test]
+    fn a_program_that_ignores_sighup_ends_when_the_pty_closes() {
+        close_after_ready("trap '' HUP; printf READY; exec cat", "exit status: 0");
+    }
+
     #[test]
     fn a_missing_folder_stops_the_start() {
         let launch = Launch {

src/term/unix.rs

@@ -3,7 +3,7 @@ use std::{
     ffi::{CStr, CString},
     fs::File,
     io::{self, ErrorKind, Read},
-    mem::MaybeUninit,
+    mem::{ManuallyDrop, MaybeUninit},
     os::{
         fd::AsRawFd,
         unix::{ffi::OsStrExt, net::UnixStream, process::CommandExt},
@@ -35,7 +35,7 @@ const CHILD: usize = 1;
 /// A program on a pseudo-terminal, started here so a failed `chdir` fails the start.
 pub(crate) struct Pty {
     child: Child,
-    file: File,
+    file: ManuallyDrop<File>,
     signals: UnixStream,
     sig: SigId,
 }
@@ -119,7 +119,7 @@ pub(crate) fn spawn(
     }
     Ok(Pty {
         child,
-        file: File::from(master),
+        file: ManuallyDrop::new(File::from(master)),
         signals,
         sig,
     })
@@ -214,7 +214,7 @@ impl EventedReadWrite for Pty {
     ) -> io::Result<()> {
         interest.key = READ_WRITE;
         unsafe {
-            poll.add_with_mode(&self.file, interest, mode)?;
+            poll.add_with_mode(&*self.file, interest, mode)?;
             poll.add_with_mode(&self.signals, Event::readable(CHILD), PollMode::Level)
         }
     }
@@ -226,12 +226,12 @@ impl EventedReadWrite for Pty {
         mode: PollMode,
     ) -> io::Result<()> {
         interest.key = READ_WRITE;
-        poll.modify_with_mode(&self.file, interest, mode)?;
+        poll.modify_with_mode(&*self.file, interest, mode)?;
         poll.modify_with_mode(&self.signals, Event::readable(CHILD), PollMode::Level)
     }
 
     fn deregister(&mut self, poll: &Arc<Poller>) -> io::Result<()> {
-        poll.delete(&self.file)?;
+        poll.delete(&*self.file)?;
         poll.delete(&self.signals)
     }
 
@@ -284,6 +284,8 @@ impl Drop for Pty {
     fn drop(&mut self) {
         unsafe { libc::kill(self.child.id() as libc::pid_t, libc::SIGHUP) };
         unregister(self.sig);
+        // Closed before the wait, so a program that ignores SIGHUP reads EOF.
+        unsafe { ManuallyDrop::drop(&mut self.file) };
         match self.child.wait() {
             Ok(status) => log::info!("pty {}: hung up, {status}", self.id()),
             Err(error) => log::error!("pty {}: cannot reap the program: {error}", self.id()),