File 0002-Read-and-write-autologin-user-to-etc-sysconfig-displ.patch of Package kcm_sddm

From 338984a86f06022241ee2d34cfad2bcac672dde1 Mon Sep 17 00:00:00 2001
From: Fabian Vogt <fabian@ritter-vogt.de>
Date: Tue, 19 Jan 2021 20:45:33 +0100
Subject: [PATCH 2/3] Read and write autologin user to
 /etc/sysconfig/displaymanager

That's where SDDM reads from.
---
 sddmauthhelper.cpp       | 30 ++++++++++++++++++++++++++++++
 src/sddmsettingsbase.cpp |  6 ++++--
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/sddmauthhelper.cpp b/sddmauthhelper.cpp
index 8a67635..fcb72fd 100644
--- a/sddmauthhelper.cpp
+++ b/sddmauthhelper.cpp
@@ -28,6 +28,8 @@
 #include <QMimeDatabase>
 #include <QMimeType>
 #include <QSharedPointer>
+#include <QSaveFile>
+#include <QRegularExpression>
 
 #include <KArchive>
 #include <KConfig>
@@ -252,6 +254,34 @@ ActionReply SddmAuthHelper::save(const QVariantMap &args)
         QString groupName = configFields[1];
         QString keyName = configFields[2];
 
+        if (groupName == QLatin1String("Autologin") && keyName == QLatin1String("User")) {
+			QString sysconfFileName = QStringLiteral("/etc/sysconfig/displaymanager");
+            QFile sysconf(sysconfFileName);
+			QSaveFile newconf(sysconfFileName);
+            if (!sysconf.open(QIODevice::ReadOnly) || !newconf.open(QIODevice::WriteOnly)) {
+				return ActionReply::HelperErrorReply();
+			}
+
+            QString sysconfData = QString::fromUtf8(sysconf.readAll());
+			if (sysconfData.isEmpty()) {
+				return ActionReply::HelperErrorReply();
+			}
+
+			QRegularExpression re(QStringLiteral("^DISPLAYMANAGER_AUTOLOGIN=.*$"), QRegularExpression::MultilineOption);
+			auto match = re.match(sysconfData);
+			if (!match.hasMatch()) {
+				return ActionReply::HelperErrorReply();
+			}
+
+			sysconfData.replace(match.capturedStart(), match.capturedLength(),
+								QStringLiteral("DISPLAYMANAGER_AUTOLOGIN=\"%0\"").arg(iterator.value().toString()));
+
+			QByteArray newData = sysconfData.toUtf8();
+			if (newconf.write(newData) != newData.length() || !newconf.commit()) {
+				return ActionReply::HelperErrorReply();
+			}
+        }
+
         // if there is an identical keyName in "sddm.conf" we want to delete it so SDDM doesn't read from the old file
         // hierarchically SDDM prefers "etc/sddm.conf" to "/etc/sddm.conf.d/some_file.conf"
 
diff --git a/src/sddmsettingsbase.cpp b/src/sddmsettingsbase.cpp
index e8aa915..1e3e52d 100644
--- a/src/sddmsettingsbase.cpp
+++ b/src/sddmsettingsbase.cpp
@@ -21,6 +21,7 @@
 
 #include <QDebug>
 #include <QDir>
+#include <QSettings>
 
 #include <algorithm>
 
@@ -57,12 +58,13 @@ unsigned int SddmSettingsBase::defaultMaximumUid() const
 
 QString SddmSettingsBase::defaultUser() const
 {
-    return m_defaultConfig->group("AutoLogin").readEntry("User");
+    QSettings sysconfSettings(QStringLiteral("/etc/sysconfig/displaymanager"), QSettings::IniFormat);
+    return sysconfSettings.value(QStringLiteral("DISPLAYMANAGER_AUTOLOGIN")).toString();
 }
 
 QString SddmSettingsBase::defaultSession() const
 {
-    return m_defaultConfig->group("AutoLogin").readEntry("Session");
+    return m_defaultConfig->group("AutoLogin").readEntry("Session", "default.desktop");
 }
 
 bool SddmSettingsBase::defaultRelogin() const
-- 
2.25.1