fix: allow treeland to start without any users

src/core/treeland.cpp

@@ -1,4 +1,4 @@
-// Copyright (C) 2023 Dingyuan Zhang <lxz@mkacg.com>.
+// Copyright (C) 2023-2026 Dingyuan Zhang <lxz@mkacg.com>.
 // SPDX-License-Identifier: Apache-2.0 OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
 #include "treeland.h"
@@ -314,7 +314,10 @@ Treeland::Treeland()
     d->init();
 
     auto globalSession = d->helper->sessionManager()->globalSession();
-    Q_ASSERT(globalSession);
+    if (!globalSession) {
+        qCCritical(lcTlCore) << "Global session is null, skipping initialization";
+        return;
+    }
 
     if (CmdLine::ref().run().has_value()) {
         auto exec = [runCmd = CmdLine::ref().run().value(), d, globalSession] {

src/greeter/usermodel.cpp

@@ -63,7 +63,8 @@ UserModel::UserModel(QObject *parent)
 
     auto userList = d->manager.userList();
     if (!userList) {
-        qFatal() << userList.error();
+        qCWarning(lcTlGreeter) << "Failed to get user list:" << userList.error();
+        return;
     }
 
     const auto uids = userList.value();
@@ -95,8 +96,12 @@ UserModel::UserModel(QObject *parent)
     }
 
     if (d->currentUserName.isEmpty()) {
-        qCWarning(lcTlGreeter) << "Couldn't find last user, using current running user as current user";
-        d->currentUserName = d->users.first()->userName();
+        if (d->users.isEmpty()) {
+            qCWarning(lcTlGreeter) << "No users found, currentUserName remains empty";
+        } else {
+            qCWarning(lcTlGreeter) << "Couldn't find last user, using current running user as current user";
+            d->currentUserName = d->users.first()->userName();
+        }
     }
 }
 

src/session/session.cpp

@@ -15,10 +15,11 @@
 
 #include <woutputrenderwindow.h>
 #include <wsocket.h>
 #include <wxwayland.h>
 
 #include <pwd.h>
+#include <unistd.h>
 #include <xcb/randr.h>
 
 #define _DEEPIN_NO_TITLEBAR "_DEEPIN_NO_TITLEBAR"
 
@@ -381,8 +382,13 @@
     // Session does not exist, create new session with deleter
     auto passwd = getpwnam(username.toLocal8Bit().data());
     if (!passwd) {
-        qCWarning(lcTlCore) << "Failed to get passwd entry for user:" << username;
-        return nullptr;
+        qCWarning(lcTlCore) << "Failed to get passwd entry for user:" << username
+                            << ", falling back to current user uid";
+        passwd = getpwuid(getuid());
+        if (!passwd) {
+            qCCritical(lcTlCore) << "Failed to get passwd entry for current user";
+            return nullptr;
+        }
     }
     auto session = std::make_shared<Session>();
     session->m_id = id;