From 093e8e54c7de33c2d7332cc3a126041263e1aa71 Mon Sep 17 00:00:00 2001
From: davidedmundson <kde@davidedmundson.co.uk>
Date: Mon, 8 Mar 2021 07:35:55 +0000
Subject: [PATCH] Allow addition env vars to be defined in session files
 (#1370)

We have a continual problem with developers using Plasma in custom
prefixes. We need to set mulitple additional envs and it is a constant
pain point.

Setting XDG_DATA_DIRS and alike in a script in the Exec line of the
desktop file doesn't work properly, as this is after systemd and dbus
have already been started during pam_logind. It is currently very bodged
with more manual steps.

Things will work much better if we can set the env before pam_logind is
run.

Using pam_env or profile.d doesn't work as that affects all the
sessions.

It is not intended to be used for anything other than dev setups.
---
 src/common/Session.cpp | 24 ++++++++++++++++++++++++
 src/common/Session.h   |  5 +++++
 src/daemon/Display.cpp |  1 +
 3 files changed, 30 insertions(+)

diff --git a/src/common/Session.cpp b/src/common/Session.cpp
index 3de28ef13..0aa540221 100644
--- a/src/common/Session.cpp
+++ b/src/common/Session.cpp
@@ -107,6 +107,10 @@ namespace SDDM {
         return m_isNoDisplay;
     }
 
+    QProcessEnvironment Session::additionalEnv() const {
+        return m_additionalEnv;
+    }
+
     void Session::setTo(Type type, const QString &_fileName)
     {
         QString fileName(_fileName);
@@ -178,6 +182,8 @@ namespace SDDM {
                 m_isHidden = line.mid(7).toLower() == QLatin1String("true");
             if (line.startsWith(QLatin1String("NoDisplay=")))
                 m_isNoDisplay = line.mid(10).toLower() == QLatin1String("true");
+            if (line.startsWith(QLatin1String("X-SDDM-Env=")))
+                m_additionalEnv = parseEnv(line.mid(strlen("X-SDDM-Env=")));
         }
 
         file.close();
@@ -191,4 +197,22 @@ namespace SDDM {
         setTo(other.type(), other.fileName());
         return *this;
     }
+
+    QProcessEnvironment SDDM::Session::parseEnv(const QString &list)
+    {
+        QProcessEnvironment env;
+
+        const QVector<QStringRef> entryList = list.splitRef(QLatin1Char(','));
+        for (const auto &entry: entryList) {
+            int midPoint = entry.indexOf(QLatin1Char('='));
+            if (midPoint < 0) {
+                qWarning() << "Malformed entry in" << fileName() << ":" << entry;
+                continue;
+            }
+            env.insert(entry.left(midPoint).toString(), entry.mid(midPoint+1).toString());
+        }
+        return env;
+    }
+
+
 }
diff --git a/src/common/Session.h b/src/common/Session.h
index 9fd86cd02..aa196e9c6 100644
--- a/src/common/Session.h
+++ b/src/common/Session.h
@@ -23,6 +23,7 @@
 #include <QDataStream>
 #include <QDir>
 #include <QSharedPointer>
+#include <QProcessEnvironment>
 
 namespace SDDM {
     class SessionModel;
@@ -59,11 +60,14 @@ namespace SDDM {
         bool isHidden() const;
         bool isNoDisplay() const;
 
+        QProcessEnvironment additionalEnv() const;
+
         void setTo(Type type, const QString &name);
 
         Session &operator=(const Session &other);
 
     private:
+        QProcessEnvironment parseEnv(const QString &list);
         bool m_valid;
         Type m_type;
         QDir m_dir;
@@ -75,6 +79,7 @@ namespace SDDM {
         QString m_tryExec;
         QString m_xdgSessionType;
         QString m_desktopNames;
+        QProcessEnvironment m_additionalEnv;
         bool m_isHidden;
         bool m_isNoDisplay;
 
diff --git a/src/daemon/Display.cpp b/src/daemon/Display.cpp
index 9f1fabc68..a65df3f0b 100644
--- a/src/daemon/Display.cpp
+++ b/src/daemon/Display.cpp
@@ -313,6 +313,7 @@ namespace SDDM {
         qDebug() << "Session" << m_sessionName << "selected, command:" << session.exec();
 
         QProcessEnvironment env;
+        env.insert(session.additionalEnv());
 
         if (seat()->name() == QLatin1String("seat0")) {
             // Use the greeter VT, for wayland sessions the helper overwrites this