From a8573ccc35a4efe8900be5d48c6c803670540c2b Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 1 Oct 2012 14:50:00 -0400
Subject: [PATCH] pam: check environ[] for XDG_SEAT as fallback

This is useful for systems such as kmscon which want to invoke classic
/sbin/login but use it on multiple seats.
---
 src/login/pam-module.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/login/pam-module.c b/src/login/pam-module.c
index 0d387918c7..af108c46d5 100644
--- a/src/login/pam-module.c
+++ b/src/login/pam-module.c
@@ -428,8 +428,14 @@ _public_ PAM_EXTERN int pam_sm_open_session(
         pam_get_item(handle, PAM_TTY, (const void**) &tty);
         pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);
         pam_get_item(handle, PAM_RHOST, (const void**) &remote_host);
+
         seat = pam_getenv(handle, "XDG_SEAT");
+        if (isempty(seat))
+                seat = getenv("XDG_SEAT");
+
         cvtnr = pam_getenv(handle, "XDG_VTNR");
+        if (isempty(cvtnr))
+                cvtnr = getenv("XDG_VTNR");
 
         service = strempty(service);
         tty = strempty(tty);
@@ -467,6 +473,8 @@ _public_ PAM_EXTERN int pam_sm_open_session(
                    !isempty(tty) ? "tty" : "unspecified";
 
         class = pam_getenv(handle, "XDG_SESSION_CLASS");
+        if (isempty(class))
+                class = getenv("XDG_SESSION_CLASS");
         if (isempty(class))
                 class = "user";