Spawn children from foreground working directory

To allow applications spawned by Alacritty to make use of the
shell/foreground process' working directory, it is now set for all new
processes spawned by Alacritty on Unix platforms.

Fixes #5616.

Co-authored-by: Christian Duerr <contact@christianduerr.com>

3 files changed, 49 insertions, 44 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64cd7c5e..69623b97 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Reload configuration files when their symbolic link is replaced
 - Strip trailing whitespaces when yanking from a block selection
 - Display area keeps history position when viewport is cleared
+- Commands spawn from the current directory of the foreground shell in Unix-like systems
 
 ### Fixed
 
diff --git a/alacritty/src/daemon.rs b/alacritty/src/daemon.rs
index b199c353..4b95cb6b 100644
--- a/alacritty/src/daemon.rs
+++ b/alacritty/src/daemon.rs
@@ -1,16 +1,28 @@
+#[cfg(not(windows))]
+use std::error::Error;
 use std::ffi::OsStr;
 use std::fmt::Debug;
+#[cfg(not(any(target_os = "macos", windows)))]
+use std::fs;
 use std::io;
 #[cfg(not(windows))]
 use std::os::unix::process::CommandExt;
 #[cfg(windows)]
 use std::os::windows::process::CommandExt;
+#[cfg(not(windows))]
+use std::path::PathBuf;
 use std::process::{Command, Stdio};
 
 use log::{debug, warn};
 #[cfg(windows)]
 use winapi::um::winbase::{CREATE_NEW_PROCESS_GROUP, CREATE_NO_WINDOW};
 
+#[cfg(not(windows))]
+use alacritty_terminal::tty;
+
+#[cfg(target_os = "macos")]
+use crate::macos;
+
 /// Start the daemon and log error on failure.
 pub fn start_daemon<I, S>(program: &str, args: I)
 where
@@ -43,18 +55,41 @@ where
         .map(|_| ())
 }
 
+/// Get working directory of controlling process.
+#[cfg(not(windows))]
+pub fn foreground_process_path() -> Result<PathBuf, Box<dyn Error>> {
+    let mut pid = unsafe { libc::tcgetpgrp(tty::master_fd()) };
+    if pid < 0 {
+        pid = tty::child_pid();
+    }
+
+    #[cfg(not(any(target_os = "macos", target_os = "freebsd")))]
+    let link_path = format!("/proc/{}/cwd", pid);
+    #[cfg(target_os = "freebsd")]
+    let link_path = format!("/compat/linux/proc/{}/cwd", pid);
+
+    #[cfg(not(target_os = "macos"))]
+    let cwd = fs::read_link(link_path)?;
+
+    #[cfg(target_os = "macos")]
+    let cwd = macos::proc::cwd(pid)?;
+
+    Ok(cwd)
+}
+
 #[cfg(not(windows))]
 fn spawn_daemon<I, S>(program: &str, args: I) -> io::Result<()>
 where
     I: IntoIterator<Item = S> + Copy,
     S: AsRef<OsStr>,
 {
+    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() {
+        command.current_dir(cwd);
+    }
     unsafe {
-        Command::new(program)
-            .args(args)
-            .stdin(Stdio::null())
-            .stdout(Stdio::null())
-            .stderr(Stdio::null())
+        command
             .pre_exec(|| {
                 match libc::fork() {
                     -1 => return Err(io::Error::last_os_error()),
diff --git a/alacritty/src/event.rs b/alacritty/src/event.rs
index 4af372c9..7fb54b39 100644
--- a/alacritty/src/event.rs
+++ b/alacritty/src/event.rs
@@ -30,20 +30,18 @@ use alacritty_terminal::index::{Boundary, Column, Direction, Line, Point, Side};
 use alacritty_terminal::selection::{Selection, SelectionType};
 use alacritty_terminal::term::search::{Match, RegexSearch};
 use alacritty_terminal::term::{ClipboardType, SizeInfo, Term, TermMode};
-#[cfg(not(windows))]
-use alacritty_terminal::tty;
 
 use crate::cli::{Options as CliOptions, TerminalOptions as TerminalCliOptions};
 use crate::clipboard::Clipboard;
 use crate::config::ui_config::{HintAction, HintInternalAction};
 use crate::config::{self, UiConfig};
+#[cfg(not(windows))]
+use crate::daemon::foreground_process_path;
 use crate::daemon::start_daemon;
 use crate::display::hint::HintMatch;
 use crate::display::window::Window;
 use crate::display::{self, Display};
 use crate::input::{self, ActionContext as _, FONT_SIZE_STEP};
-#[cfg(target_os = "macos")]
-use crate::macos;
 use crate::message_bar::{Message, MessageBuffer};
 use crate::scheduler::{Scheduler, TimerId, Topic};
 use crate::window_context::WindowContext;
@@ -354,27 +352,19 @@ impl<'a, N: Notify + 'a, T: EventListener> input::ActionContext<T> for ActionCon
         let mut env_args = env::args();
         let alacritty = env_args.next().unwrap();
 
-        // Use working directory of controlling process, or fallback to initial shell, then add it
-        // as working-directory parameter.
-        #[cfg(unix)]
-        let mut args = foreground_process_path()
-            .map(|path| vec!["--working-directory".into(), path])
-            .unwrap_or_default();
-
-        #[cfg(not(unix))]
-        let mut args: Vec<PathBuf> = Vec::new();
-
-        let working_directory_set = !args.is_empty();
+        let mut args: Vec<String> = Vec::new();
 
         // Reuse the arguments passed to Alacritty for the new instance.
+        #[allow(clippy::while_let_on_iterator)]
         while let Some(arg) = env_args.next() {
-            // Drop working directory from existing parameters.
-            if working_directory_set && arg == "--working-directory" {
+            // On unix, the working directory of the foreground shell is used by `start_daemon`.
+            #[cfg(not(windows))]
+            if arg == "--working-directory" {
                 let _ = env_args.next();
                 continue;
             }
 
-            args.push(arg.into());
+            args.push(arg);
         }
 
         start_daemon(&alacritty, &args);
@@ -1389,24 +1379,3 @@ impl EventListener for EventProxy {
         let _ = self.proxy.send_event(Event::new(event.into(), self.window_id));
     }
 }
-
-#[cfg(not(windows))]
-pub fn foreground_process_path() -> Result<PathBuf, Box<dyn Error>> {
-    let mut pid = unsafe { libc::tcgetpgrp(tty::master_fd()) };
-    if pid < 0 {
-        pid = tty::child_pid();
-    }
-
-    #[cfg(not(any(target_os = "macos", target_os = "freebsd")))]
-    let link_path = format!("/proc/{}/cwd", pid);
-    #[cfg(target_os = "freebsd")]
-    let link_path = format!("/compat/linux/proc/{}/cwd", pid);
-
-    #[cfg(not(target_os = "macos"))]
-    let cwd = std::fs::read_link(link_path)?;
-
-    #[cfg(target_os = "macos")]
-    let cwd = macos::proc::cwd(pid)?;
-
-    Ok(cwd)
-}