Set IUTF8 input setting on supported platforms

Fixes #3769.

CHANGELOG.md

@@ -30,6 +30,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Don't hide cursor on modifier press with `mouse.hide_when_typing` enabled
 - `Shift + Backspace` now sends `^?` instead of `^H`
 - Default color scheme is now `Tomorrow Night` with the bright colors of `Tomorrow Night Bright`
+- Set IUTF8 termios flag for improved UTF8 input support
 
 ### Fixed
 

alacritty_terminal/src/tty/unix.rs

@@ -22,6 +22,8 @@ use crate::tty::{ChildEvent, EventedPty, EventedReadWrite};
 use libc::{self, c_int, pid_t, winsize, TIOCSCTTY};
 use log::error;
 use nix::pty::openpty;
+#[cfg(any(target_os = "linux", target_os = "macos"))]
+use nix::sys::termios::{self, InputFlags, SetArg};
 use signal_hook::{self as sighook, iterator::Signals};
 
 use mio::unix::EventedFd;
@@ -45,7 +47,7 @@ static PID: AtomicUsize = AtomicUsize::new(0);
 macro_rules! die {
     ($($arg:tt)*) => {{
         error!($($arg)*);
-        ::std::process::exit(1);
+        std::process::exit(1);
     }}
 }
 
@@ -148,6 +150,15 @@ pub fn new<C>(config: &Config<C>, size: &SizeInfo, window_id: Option<usize>) ->
 
     let (master, slave) = make_pty(win_size);
 
+    #[cfg(any(target_os = "linux", target_os = "macos"))]
+    {
+        if let Ok(mut termios) = termios::tcgetattr(master) {
+            // Set character encoding to UTF-8.
+            termios.input_flags.set(InputFlags::IUTF8, true);
+            let _ = termios::tcsetattr(master, SetArg::TCSANOW, &termios);
+        }
+    }
+
     let default_shell = if cfg!(target_os = "macos") {
         let shell_name = pw.shell.rsplit('/').next().unwrap();
         let argv = vec![String::from("-c"), format!("exec -a -{} {}", shell_name, pw.shell)];