From b775f93c2269e7fc9dbc704464179babe2c1ca3d Mon Sep 17 00:00:00 2001
From: Jakub Krcma <jkrcma@gmail.com>
Date: Fri, 28 Feb 2020 10:50:27 +0100
Subject: [PATCH] Set locale env variables in correct order

This commit aims to fix the use case of setting multiple environment
variables in locale settings. As described in manpages, consider the
following content of `/etc/locale.conf`:

    LANG=de_DE.UTF-8
    LC_MESSAGES=en_US.UTF-8

The previous behavior caused only `LANG` to be set, leaving the other
variables intact. I am not familiar how exactly shell interprets setting
values on these values, but the value of `LC_MESSAGES` in the example
was never applied to the environment. The only way how to make it
working was to execute `unset LANG` before the `locale.conf` variables
were set.

This code snippet is heavily inspired by
https://github.com/linuxdeepin/lightdm/blob/810f9b171feb779e48eba1dca38eb37d6d027d1a/src/session-child.c
---
 src/login.c | 32 +++++++++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/login.c b/src/login.c
index 57219ae..c492647 100644
--- a/src/login.c
+++ b/src/login.c
@@ -207,11 +207,29 @@ void pam_diagnose(int error, struct term_buf* buf)
 
 void env_init(struct passwd* pwd)
 {
+	// borrowed from
+	// https://github.com/linuxdeepin/lightdm/blob/810f9b171feb779e48eba1dca38eb37d6d027d1a/src/session-child.c
+	static const char* const locale_var_names[] = {
+        "LC_PAPER",
+        "LC_NAME",
+        "LC_ADDRESS",
+        "LC_TELEPHONE",
+        "LC_MEASUREMENT",
+        "LC_IDENTIFICATION",
+        "LC_COLLATE",
+        "LC_CTYPE",
+        "LC_MONETARY",
+        "LC_NUMERIC",
+        "LC_TIME",
+        "LC_MESSAGES",
+        "LC_ALL",
+        "LANG",
+        NULL
+    };
 	extern char** environ;
 	char* term = getenv("TERM");
-	char* lang = getenv("LANG");
 	// clean env
-	environ[0] = NULL;
+	environ = NULL;
 
 	if (term != NULL)
 	{
@@ -227,7 +245,15 @@ void env_init(struct passwd* pwd)
 	setenv("SHELL", pwd->pw_shell, 1);
 	setenv("USER", pwd->pw_name, 1);
 	setenv("LOGNAME", pwd->pw_name, 1);
-	setenv("LANG", lang, 1);
+
+	char* locale_value;
+	for (int i = 0; locale_var_names[i] != NULL; i++)
+	{
+		if ((locale_value = getenv(locale_var_names[i])) != NULL)
+		{
+			setenv(locale_var_names[i], locale_value, 1);
+		}
+	}
 
 	// Set PATH if specified in the configuration
 	if (strlen(config.path))