[plasma/plasma-login-manager] src/daemon: daemon: Move autologin to seat

Git commit 491e323a9026b5547ff9c0a69f13825ccf238e7a by David Edmundson.
Committed on 26/07/2026 at 21:25.
Pushed by davidedmundson into branch 'master'.

daemon: Move autologin to seat

If we start multiple sessions we would only want to autologin to the
first. Therefore it's a property of the Seat not the Display.

This contains no behavioural changes, but is a stepping stone to a fix.

M  +18   -45   src/daemon/Display.cpp
M  +1    -3    src/daemon/Display.h
M  +26   -0    src/daemon/Seat.cpp

https://invent.kde.org/plasma/plasma-login-manager/-/commit/491e323a9026b5547ff9c0a69f13825ccf238e7a

diff --git a/src/daemon/Display.cpp b/src/daemon/Display.cpp
index c8d53fd6..5963e59c 100644
--- a/src/daemon/Display.cpp
+++ b/src/daemon/Display.cpp
@@ -37,10 +37,6 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 
-#include <KConfig>
-#include <KConfigGroup>
-#include <KDesktopFile>
-
 #include "VirtualTerminal.h"
 #include "config.h"
 
@@ -87,47 +83,6 @@ Display::Display(Seat *parent)
         VirtualTerminal::jumpToVt(PLASMALOGIN_INITIAL_VT, true);
         stop();
     });
-
-    // Per-seat autologin: a seat with its own [Autologin][<seat>] subgroup is logged in as that
-    // subgroup's User running its Session, so a dedicated seat can be driven by the login manager
-    // without the greeter claiming it. The subgroup overrides the [Autologin] keys (User, Session,
-    // Relogin) for that seat; a seat with no subgroup takes the global path unchanged.
-    QString autologinUser;
-    QString autologinSession;
-    const KConfigGroup autologinGroup = PlasmaLogin::config()->config()->group(QStringLiteral("Autologin"));
-    const bool tryLockFirstLogin = seat()->tryLockFirstLogin();
-    const QString seatName = seat()->name();
-    if (autologinGroup.hasGroup(seatName)) {
-        const KConfigGroup seatGroup = autologinGroup.group(seatName);
-        if (seatGroup.readEntry("Relogin", PlasmaLogin::config()->autologinRelogin()) || tryLockFirstLogin) {
-            autologinUser = seatGroup.readEntry("User", QString());
-            autologinSession = seatGroup.readEntry("Session", QString());
-            if (autologinUser.isEmpty()) {
-                qWarning() << "Per-seat autologin: seat" << seatName << "is configured to autologin but names no User; it will be greeted.";
-            } else {
-                qInfo() << "Per-seat autologin: seat" << seatName << "configured for user" << autologinUser << "session" << autologinSession;
-            }
-        } else {
-            qDebug() << "Per-seat autologin: seat" << seatName
-                     << "has a config subgroup but Relogin is off and this is not the first login; it will be greeted.";
-        }
-    } else if (PlasmaLogin::config()->autologinRelogin() || tryLockFirstLogin) {
-        autologinUser = PlasmaLogin::config()->autologinUser();
-        autologinSession = PlasmaLogin::config()->autologinSession();
-    }
-
-    if (!autologinUser.isEmpty()) {
-        m_autologinUser = autologinUser;
-        // determine session type
-        m_autologinSession = Session::create(Session::WaylandSession, autologinSession);
-        if (!m_autologinSession.isValid()) {
-            m_autologinSession = Session::create(Session::X11Session, autologinSession);
-        }
-        if (!m_autologinSession.isValid()) {
-            qCritical() << "Unable to find autologin session entry" << autologinSession << "for user"
-                        << autologinUser << "on seat" << seatName << "— falling back to the greeter";
-        }
-    }
 }
 
 Display::~Display()
@@ -151,6 +106,24 @@ Seat *Display::seat() const
     return m_seat;
 }
 
+void Display::setAutoLogin(const QString &user, const QString &session)
+{
+    m_autologinUser = user;
+    m_autologinSession = Session();
+    if (user.isEmpty()) {
+        return;
+    }
+
+    m_autologinSession = Session::create(Session::WaylandSession, session);
+    if (!m_autologinSession.isValid()) {
+        m_autologinSession = Session::create(Session::X11Session, session);
+    }
+    if (!m_autologinSession.isValid()) {
+        qCritical() << "Unable to find autologin session entry" << session << "for user" << user << "on seat" << seat()->name()
+                    << "— falling back to the greeter";
+    }
+}
+
 bool Display::start()
 {
     if (m_started) {
diff --git a/src/daemon/Display.h b/src/daemon/Display.h
index a04b6b81..2861ece5 100644
--- a/src/daemon/Display.h
+++ b/src/daemon/Display.h
@@ -54,6 +54,7 @@ public:
     }
 
     Seat *seat() const;
+    void setAutoLogin(const QString &user, const QString &session);
 
 public slots:
     bool start();
@@ -84,9 +85,6 @@ private:
     QString m_reuseSessionId;
 
     Session m_autologinSession;
-    // The user to autologin as. Normally PlasmaLogin::config()->autologinUser(), but for a seat
-    // with its own [Autologin][<seat>] config subgroup it is that subgroup's User= (the kiosk
-    // user on a dedicated seat). Set in the constructor, consumed by start().
     QString m_autologinUser;
 
     Auth *m_auth{nullptr};
diff --git a/src/daemon/Seat.cpp b/src/daemon/Seat.cpp
index c365afad..2b22554c 100644
--- a/src/daemon/Seat.cpp
+++ b/src/daemon/Seat.cpp
@@ -151,6 +151,32 @@ void Seat::createDisplay()
     // add display to the list
     m_displays << display;
 
+    // Per-seat autologin overrides the global [Autologin] keys for a dedicated seat.
+    // Resolve it here, after the configuration has been reloaded, rather than caching it
+    // in Display's constructor.
+    QString autologinUser;
+    QString autologinSession;
+    const bool firstLogin = tryLockFirstLogin();
+    const KConfigGroup autologinGroup = PlasmaLogin::config()->config()->group(QStringLiteral("Autologin"));
+    if (autologinGroup.hasGroup(m_name)) {
+        const KConfigGroup seatGroup = autologinGroup.group(m_name);
+        if (seatGroup.readEntry("Relogin", PlasmaLogin::config()->autologinRelogin()) || firstLogin) {
+            autologinUser = seatGroup.readEntry("User", QString());
+            autologinSession = seatGroup.readEntry("Session", QString());
+            if (autologinUser.isEmpty()) {
+                qWarning() << "Per-seat autologin: seat" << m_name << "is configured to autologin but names no User; it will be greeted.";
+            } else {
+                qInfo() << "Per-seat autologin: seat" << m_name << "configured for user" << autologinUser << "session" << autologinSession;
+            }
+        } else {
+            qDebug() << "Per-seat autologin: seat" << m_name << "has a config subgroup but Relogin is off and this is not the first login; it will be greeted.";
+        }
+    } else if (PlasmaLogin::config()->autologinRelogin() || firstLogin) {
+        autologinUser = PlasmaLogin::config()->autologinUser();
+        autologinSession = PlasmaLogin::config()->autologinSession();
+    }
+    display->setAutoLogin(autologinUser, autologinSession);
+
     // start the display
     startDisplay(display);
 }