From b82bcb3aeb96fd3a867e6e717be3b9431faa70bd Mon Sep 17 00:00:00 2001
From: Jesse Luehrs <doy@tozt.net>
Date: Thu, 30 Dec 2021 15:43:53 -0500
Subject: simplify

---
 src/blocking/command.rs |  9 +++++----
 src/command.rs          |  9 +++++----
 src/sys.rs              | 20 +++++++++++---------
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/src/blocking/command.rs b/src/blocking/command.rs
index b2ca3e4..ed36443 100644
--- a/src/blocking/command.rs
+++ b/src/blocking/command.rs
@@ -103,25 +103,26 @@ impl Command {
         &mut self,
         pty: &crate::blocking::Pty,
     ) -> crate::Result<std::process::Child> {
-        let (stdin, stdout, stderr, mut pre_exec) =
-            crate::sys::setup_subprocess(pty.pts())?;
+        let pts = pty.pts();
+        let (stdin, stdout, stderr) = crate::sys::setup_subprocess(pts)?;
 
         self.inner.stdin(self.stdin.take().unwrap_or(stdin));
         self.inner.stdout(self.stdout.take().unwrap_or(stdout));
         self.inner.stderr(self.stderr.take().unwrap_or(stderr));
 
+        let mut session_leader = crate::sys::session_leader(pts);
         // safe because setsid() is an async-signal-safe function and ioctl()
         // is a raw syscall (which is inherently async-signal-safe).
         if let Some(mut custom) = self.pre_exec.take() {
             unsafe {
                 self.inner.pre_exec(move || {
-                    pre_exec()?;
+                    session_leader()?;
                     custom()?;
                     Ok(())
                 })
             };
         } else {
-            unsafe { self.inner.pre_exec(pre_exec) };
+            unsafe { self.inner.pre_exec(session_leader) };
         }
 
         Ok(self.inner.spawn()?)
diff --git a/src/command.rs b/src/command.rs
index c50af30..cd1c8a3 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -103,25 +103,26 @@ impl Command {
         &mut self,
         pty: &crate::Pty,
     ) -> crate::Result<async_process::Child> {
-        let (stdin, stdout, stderr, mut pre_exec) =
-            crate::sys::setup_subprocess(pty.pts())?;
+        let pts = pty.pts();
+        let (stdin, stdout, stderr) = crate::sys::setup_subprocess(pts)?;
 
         self.inner.stdin(self.stdin.take().unwrap_or(stdin));
         self.inner.stdout(self.stdout.take().unwrap_or(stdout));
         self.inner.stderr(self.stderr.take().unwrap_or(stderr));
 
+        let mut session_leader = crate::sys::session_leader(pts);
         // Safety: setsid() is an async-signal-safe function and ioctl() is a
         // raw syscall (which is inherently async-signal-safe).
         if let Some(mut custom) = self.pre_exec.take() {
             unsafe {
                 self.inner.pre_exec(move || {
-                    pre_exec()?;
+                    session_leader()?;
                     custom()?;
                     Ok(())
                 })
             };
         } else {
-            unsafe { self.inner.pre_exec(pre_exec) };
+            unsafe { self.inner.pre_exec(session_leader) };
         }
 
         Ok(self.inner.spawn()?)
diff --git a/src/sys.rs b/src/sys.rs
index b837949..0d897bc 100644
--- a/src/sys.rs
+++ b/src/sys.rs
@@ -46,7 +46,6 @@ pub fn setup_subprocess(
     std::process::Stdio,
     std::process::Stdio,
     std::process::Stdio,
-    impl FnMut() -> std::io::Result<()>,
 )> {
     let pts_fd = pts.as_raw_fd();
 
@@ -63,17 +62,20 @@ pub fn setup_subprocess(
         unsafe { std::process::Stdio::from_raw_fd(stdin) },
         unsafe { std::process::Stdio::from_raw_fd(stdout) },
         unsafe { std::process::Stdio::from_raw_fd(stderr) },
-        move || {
-            nix::unistd::setsid()?;
-            set_controlling_terminal(pts_fd)?;
-
-            // no need to close anything, since we set cloexec everywhere
-
-            Ok(())
-        },
     ))
 }
 
+pub fn session_leader(
+    pts: &impl std::os::unix::io::AsRawFd,
+) -> impl FnMut() -> std::io::Result<()> {
+    let pts_fd = pts.as_raw_fd();
+    move || {
+        nix::unistd::setsid()?;
+        set_controlling_terminal(pts_fd)?;
+        Ok(())
+    }
+}
+
 fn set_controlling_terminal(fd: std::os::unix::io::RawFd) -> nix::Result<()> {
     // Safety: std::fs::File is required to contain a valid file descriptor
     unsafe { set_controlling_terminal_unsafe(fd, std::ptr::null()) }
-- 
cgit v1.2.3-54-g00ecf