fix: Use iso-codes package for languages

This fixes the issue where "ber" wasn't mapped to any name, and showed
up as a blank link at the end of the language list in the installer. Now
it is listed as Berber "languages".

crates/locales/Cargo.toml

@@ -13,7 +13,6 @@ edition = "2018"
 [dependencies]
 distinst-utils = { path = "../utils/" }
 gettext-rs = "0.4.4"
-isolang = "1.0.0"
 lazy_static = "1.4.0"
 once_cell = "1.5.2"
 serde = "1.0.106"

crates/locales/src/iso639.rs

@@ -0,0 +1,40 @@
+use once_cell::sync::Lazy;
+use serde_json::from_reader;
+use std::collections::HashMap;
+use std::fs::File;
+
+const JSON_PATH_3: &str = "/usr/share/iso-codes/json/iso_639-3.json";
+const JSON_PATH_5: &str = "/usr/share/iso-codes/json/iso_639-5.json";
+
+#[derive(Debug, Deserialize)]
+pub struct Language {
+    alpha_2: Option<String>,
+    alpha_3: String,
+    pub name: String,
+}
+
+impl Language {
+    pub fn all() -> &'static [Self] {
+        static LANGUAGES: Lazy<Vec<Language>> = Lazy::new(|| {
+            let f = File::open(JSON_PATH_3).unwrap();
+            let mut m: HashMap<String, Vec<Language>> = from_reader(f).unwrap();
+            let mut languages = m.remove("639-3").unwrap();
+
+            // Language families, like Berber, which is needed
+            let f = File::open(JSON_PATH_5).unwrap();
+            let mut m: HashMap<String, Vec<Language>> = from_reader(f).unwrap();
+            languages.extend(m.remove("639-5").unwrap());
+
+            languages
+        });
+        Lazy::force(&LANGUAGES).as_slice()
+    }
+
+    pub fn from_alpha_2(alpha_2: &str) -> Option<&'static Self> {
+        Self::all().iter().find(|i| i.alpha_2.as_ref().map(String::as_str) == Some(alpha_2))
+    }
+
+    pub fn from_alpha_3(alpha_3: &str) -> Option<&'static Self> {
+        Self::all().iter().find(|i| i.alpha_3 == alpha_3)
+    }
+}

crates/locales/src/iso_codes.rs

@@ -1,15 +1,15 @@
 use super::get_default;
 use gettextrs::*;
-use isolang::Language;
 use std::env;
 
 use crate::iso3166_1::Country;
+use crate::iso639::Language;
 
 /// Fetch the ISO 639 name of a language code.
 pub fn get_language_name(code: &str) -> Option<&'static str> {
     match code.len() {
-        2 => Language::from_639_1(code).map(|x| x.to_name()),
-        3 => Language::from_639_3(code).map(|x| x.to_name()),
+        2 => Language::from_alpha_2(code).map(|x| x.name.as_str()),
+        3 => Language::from_alpha_3(code).map(|x| x.name.as_str()),
         _ => None,
     }
 }

crates/locales/src/lib.rs

@@ -3,7 +3,6 @@
 
 extern crate distinst_utils as misc;
 extern crate gettextrs;
-extern crate isolang;
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
@@ -12,6 +11,7 @@ extern crate serde_xml_rs;
 
 mod i18n;
 mod iso3166_1;
+mod iso639;
 mod iso_codes;
 mod keyboard_layout;
 mod main_countries;