Dont fail exec() on deleted directories

Use the `std::env::set_current_dir` from the `pre_exec` and ignore
error, since not changing working directory is a side effect which
shouldn't break spawning a program or block window creation.

Signed-off-by: Tycho Andersen <tycho@tycho.pizza>
Co-authored-by: Kirill Chibisov <contact@kchibisov.com>
Co-authored-by: Christian Duerr <contact@christianduerr.com>

4 files changed, 19 insertions, 13 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51ddf861..32934a17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ Notable changes to the `alacritty_terminal` crate are documented in its
 
 - Crash when OpenGL context resets
 - Modifiers being out of sync for fast/synthetic input on X11
+- Child process creation failing while inside a deleted directory
 
 ## 0.15.0
 
diff --git a/alacritty/src/daemon.rs b/alacritty/src/daemon.rs
index c8fb88d1..fa530fa0 100644
--- a/alacritty/src/daemon.rs
+++ b/alacritty/src/daemon.rs
@@ -9,6 +9,7 @@ use std::process::{Command, Stdio};
 #[rustfmt::skip]
 #[cfg(not(windows))]
 use {
+    std::env,
     std::error::Error,
     std::os::unix::process::CommandExt,
     std::os::unix::io::RawFd,
@@ -58,18 +59,22 @@ where
 {
     let mut command = Command::new(program);
     command.args(args).stdin(Stdio::null()).stdout(Stdio::null()).stderr(Stdio::null());
-    if let Ok(cwd) = foreground_process_path(master_fd, shell_pid) {
-        command.current_dir(cwd);
-    }
+
+    let working_directory = foreground_process_path(master_fd, shell_pid).ok();
     unsafe {
         command
-            .pre_exec(|| {
+            .pre_exec(move || {
                 match libc::fork() {
                     -1 => return Err(io::Error::last_os_error()),
                     0 => (),
                     _ => libc::_exit(0),
                 }
 
+                // Copy foreground process' working directory, ignoring invalid paths.
+                if let Some(working_directory) = working_directory.as_ref() {
+                    let _ = env::set_current_dir(working_directory);
+                }
+
                 if libc::setsid() == -1 {
                     return Err(io::Error::last_os_error());
                 }
diff --git a/alacritty/src/event.rs b/alacritty/src/event.rs
index 888bec4f..c761f5ae 100644
--- a/alacritty/src/event.rs
+++ b/alacritty/src/event.rs
@@ -844,9 +844,8 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
     #[cfg(not(windows))]
     fn create_new_window(&mut self, #[cfg(target_os = "macos")] tabbing_id: Option<String>) {
         let mut options = WindowOptions::default();
-        if let Ok(working_directory) = foreground_process_path(self.master_fd, self.shell_pid) {
-            options.terminal_options.working_directory = Some(working_directory);
-        }
+        options.terminal_options.working_directory =
+            foreground_process_path(self.master_fd, self.shell_pid).ok();
 
         #[cfg(target_os = "macos")]
         {
@@ -875,7 +874,7 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
 
         match result {
             Ok(_) => debug!("Launched {} with args {:?}", program, args),
-            Err(_) => warn!("Unable to launch {} with args {:?}", program, args),
+            Err(err) => warn!("Unable to launch {program} with args {args:?}: {err}"),
         }
     }
 
diff --git a/alacritty_terminal/src/tty/unix.rs b/alacritty_terminal/src/tty/unix.rs
index 6565f20b..e3db51fb 100644
--- a/alacritty_terminal/src/tty/unix.rs
+++ b/alacritty_terminal/src/tty/unix.rs
@@ -231,6 +231,7 @@ pub fn from_fd(config: &Options, window_id: u64, master: OwnedFd, slave: OwnedFd
     builder.env_remove("XDG_ACTIVATION_TOKEN");
     builder.env_remove("DESKTOP_STARTUP_ID");
 
+    let working_directory = config.working_directory.clone();
     unsafe {
         builder.pre_exec(move || {
             // Create a new process group.
@@ -239,6 +240,11 @@ pub fn from_fd(config: &Options, window_id: u64, master: OwnedFd, slave: OwnedFd
                 return Err(Error::new(ErrorKind::Other, "Failed to set session id"));
             }
 
+            // Set working directory, ignoring invalid paths.
+            if let Some(working_directory) = working_directory.as_ref() {
+                let _ = env::set_current_dir(working_directory);
+            }
+
             set_controlling_terminal(slave_fd);
 
             // No longer need slave/master fds.
@@ -256,11 +262,6 @@ pub fn from_fd(config: &Options, window_id: u64, master: OwnedFd, slave: OwnedFd
         });
     }
 
-    // Handle set working directory option.
-    if let Some(dir) = &config.working_directory {
-        builder.current_dir(dir);
-    }
-
     // Prepare signal handling before spawning child.
     let (signals, sig_id) = {
         let (sender, recv) = UnixStream::pair()?;