Write lnf defaults on startup

kcms/lookandfeel/lookandfeelmanager.cpp

@@ -208,11 +208,7 @@ void LookAndFeelManager::writeNewDefaults(KConfig &config,
 
 void LookAndFeelManager::writeNewDefaults(KConfigGroup &cg, KConfigGroup &cgd, const QString &key, const QString &value, KConfig::WriteConfigFlags writeFlags)
 {
-    if (m_data->isDefaults()) {
-        cgd.revertToDefault(key);
-    } else {
-        cgd.writeEntry(key, value, writeFlags);
-    }
+    cgd.writeEntry(key, value, writeFlags);
     cgd.sync();
 
     if (m_mode == Mode::Apply) {
@@ -356,6 +352,10 @@ void LookAndFeelManager::save(const KPackage::Package &package, const KPackage::
         setSplashScreen(m_data->settings()->lookAndFeelPackage());
         setLockScreen(m_data->settings()->lookAndFeelPackage());
 
+        QFile packageFile(QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation) + QLatin1String("/kdedefaults/package"));
+        packageFile.open(QIODevice::WriteOnly);
+        packageFile.write(m_data->settings()->lookAndFeelPackage().toUtf8());
+
         if (m_mode == Mode::Defaults) {
             return;
         }

startkde/CMakeLists.txt

@@ -22,8 +22,10 @@ target_link_libraries(startplasma PUBLIC
     Qt::DBus
     KF5::ConfigCore
     KF5::Notifications
+    KF5::Package
     ${PHONON_LIBRARIES}
     PW::KWorkspace
+    lookandfeelmanager
 )
 
 add_executable(startplasma-x11 ${START_PLASMA_COMMON_SRCS} startplasma-x11.cpp kcheckrunning/kcheckrunning.cpp)

startkde/startplasma.cpp

@@ -18,6 +18,8 @@
 #include <KConfig>
 #include <KConfigGroup>
 #include <KNotifyConfig>
+#include <KPackage/Package>
+#include <KPackage/PackageLoader>
 #include <KSharedConfig>
 
 #include <phonon/audiooutput.h>
@@ -32,6 +34,7 @@
 #include "startplasma.h"
 
 #include "../config-workspace.h"
+#include "../kcms/lookandfeel/lookandfeelmanager.h"
 #include "debug.h"
 
 QTextStream out(stderr);
@@ -357,7 +360,19 @@ void setupPlasmaEnvironment()
         currentConfigDirs = "/etc/xdg";
     }
     const auto extraConfigDir = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation).toUtf8() + "/kdedefaults";
+    QDir().mkpath(QString::fromUtf8(extraConfigDir));
     qputenv("XDG_CONFIG_DIRS", extraConfigDir + ":" + currentConfigDirs);
+
+    const KConfig globals;
+    const QString currentLnf = KConfigGroup(&globals, QStringLiteral("KDE")).readEntry("LookAndFeelPackage", QStringLiteral("org.kde.breeze.desktop"));
+    QFile activeLnf(QString::fromUtf8(extraConfigDir + "/package"));
+    activeLnf.open(QIODevice::ReadOnly);
+    if (activeLnf.readLine() != currentLnf.toUtf8()) {
+        KPackage::Package package = KPackage::PackageLoader::self()->loadPackage(QStringLiteral("Plasma/LookAndFeel"), currentLnf);
+        LookAndFeelManager lnfManager;
+        lnfManager.setMode(LookAndFeelManager::Mode::Defaults);
+        lnfManager.save(package, KPackage::Package());
+    }
 }
 
 void setupX11()