fix: set language environment in proper way (#2070)

Cargo.lock

@@ -2694,6 +2694,7 @@ dependencies = [
  "alacritty_terminal",
  "anyhow",
  "clap",
+ "cocoa",
  "crossbeam-channel",
  "directories",
  "dyn-clone",
@@ -2710,11 +2711,13 @@ dependencies = [
  "lapce-core",
  "lapce-rpc",
  "lapce-xi-rope",
+ "libc",
  "locale_config",
  "log 0.4.17",
  "lsp-types",
  "mio 0.6.23",
  "notify",
+ "objc",
  "once_cell",
  "parking_lot 0.11.2",
  "psp-types",

lapce-proxy/Cargo.toml

@@ -68,3 +68,8 @@ wasi-common = "1.0.0"
 [dependencies.wasi-experimental-http-wasmtime]
 git = "https://github.com/lapce/wasi-experimental-http"
 # path = "../../wasi-experimental-http/crates/wasi-experimental-http-wasmtime"
+
+[target.'cfg(target_os = "macos")'.dependencies]
+cocoa = "0.24"
+objc = "0.2"
+libc = "0.2"

lapce-proxy/src/terminal.rs

@@ -328,12 +328,69 @@ fn set_current(&mut self, new: Option<Writing>) {
     }
 }
 
+/// Code taken (and slightly modified) from wezterm's env-bootstrap
+/// Source: https://github.com/wez/wezterm/blob/691ec187ba29fcae45ddf4e4f88fd02c49988c86/env-bootstrap/src/lib.rs#L86
+/// License: https://github.com/wez/wezterm/blob/691ec187ba29fcae45ddf4e4f88fd02c49988c86/LICENSE.md
+/// SPDX: MIT
 #[cfg(target_os = "macos")]
 fn set_locale_environment() {
-    let locale = locale_config::Locale::global_default()
-        .to_string()
-        .replace('-', "_");
-    std::env::set_var("LC_ALL", locale + ".UTF-8");
+    use cocoa::base::id;
+    use cocoa::foundation::NSString;
+    use objc::runtime::Object;
+    use objc::*;
+
+    fn lang_is_set() -> bool {
+        match std::env::var_os("LANG") {
+            None => false,
+            Some(lang) => !lang.is_empty(),
+        }
+    }
+
+    if !lang_is_set() {
+        unsafe fn nsstring_to_str<'a>(ns: *mut Object) -> &'a str {
+            let data = NSString::UTF8String(ns as id) as *const u8;
+            let len = NSString::len(ns as id);
+            let bytes = std::slice::from_raw_parts(data, len);
+            std::str::from_utf8_unchecked(bytes)
+        }
+
+        unsafe {
+            let locale: *mut Object =
+                msg_send![class!(NSLocale), autoupdatingCurrentLocale];
+            let lang_code_obj: *mut Object = msg_send![locale, languageCode];
+            let country_code_obj: *mut Object = msg_send![locale, countryCode];
+
+            {
+                let lang_code = nsstring_to_str(lang_code_obj);
+                let country_code = nsstring_to_str(country_code_obj);
+
+                let candidate = format!("{lang_code}_{country_code}.UTF-8");
+                let candidate_cstr =
+                    std::ffi::CString::new(<&[u8]>::clone(&candidate.as_bytes()))
+                        .expect("make cstr from str");
+
+                // If this looks like a working locale then export it to
+                // the environment so that our child processes inherit it.
+                let old = libc::setlocale(libc::LC_CTYPE, std::ptr::null());
+                if !libc::setlocale(libc::LC_CTYPE, candidate_cstr.as_ptr())
+                    .is_null()
+                {
+                    std::env::set_var("LANG", &candidate);
+                } else {
+                    log::warn!(
+                        "setlocale({}) failed, fall back to en_US.UTF-8",
+                        candidate
+                    );
+                    std::env::set_var("LANG", "en_US.UTF-8");
+                }
+                libc::setlocale(libc::LC_CTYPE, old);
+            }
+
+            let _: () = msg_send![lang_code_obj, release];
+            let _: () = msg_send![country_code_obj, release];
+            let _: () = msg_send![locale, release];
+        }
+    }
 }
 
 #[inline]