Don't show the back button when startup fails

briar-desktop/src/main/kotlin/org/briarproject/briar/desktop/login/ErrorSubViewModel.kt

 /*
  * Briar Desktop
- * Copyright (C) 2021-2022 The Briar Project
+ * Copyright (C) 2021-2023 The Briar Project
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -21,7 +21,7 @@ package org.briarproject.briar.desktop.login
 class ErrorSubViewModel(
     private val viewModel: StartupViewModel,
     val error: Error,
-    val onBackButton: (() -> Unit)?,
+    val onBackButton: (() -> Unit)? = null,
 ) : StartupViewModel.SubViewModel {
     sealed interface Error
 }

briar-desktop/src/main/kotlin/org/briarproject/briar/desktop/login/RegistrationSubViewModel.kt

 /*
  * Briar Desktop
- * Copyright (C) 2021-2022 The Briar Project
+ * Copyright (C) 2021-2023 The Briar Project
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -122,7 +122,7 @@ class RegistrationSubViewModel(
                 viewModel.startBriarCore()
             } else {
                 LOG.w { "Failed to create account" }
-                viewModel.showError(RegistrationError)
+                viewModel.showError(RegistrationError, true)
             }
         }
     }

briar-desktop/src/main/kotlin/org/briarproject/briar/desktop/login/StartupViewModel.kt

 /*
  * Briar Desktop
- * Copyright (C) 2021-2022 The Briar Project
+ * Copyright (C) 2021-2023 The Briar Project
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -82,12 +82,16 @@ constructor(
         _currentSubViewModel.value = makeRegistration()
     }
 
-    private fun makeError(error: ErrorSubViewModel.Error) = ErrorSubViewModel(
-        this, error, onBackButton = { _currentSubViewModel.value = decideSubViewModel() }
-    )
+    private fun makeError(error: ErrorSubViewModel.Error, allowBackNavigation: Boolean): ErrorSubViewModel {
+        return if (allowBackNavigation) {
+            ErrorSubViewModel(this, error, onBackButton = { _currentSubViewModel.value = decideSubViewModel() })
+        } else {
+            ErrorSubViewModel(this, error)
+        }
+    }
 
-    fun showError(error: ErrorSubViewModel.Error) {
-        _currentSubViewModel.value = makeError(error)
+    fun showError(error: ErrorSubViewModel.Error, allowBackNavigation: Boolean) {
+        _currentSubViewModel.value = makeError(error, allowBackNavigation)
     }
 
     private fun makeAbout(previous: SubViewModel) =
@@ -110,7 +114,7 @@ constructor(
             ALREADY_RUNNING -> LOG.i { "Already running" }
             else -> {
                 LOG.w { "Startup failed: $result" }
-                showError(StartingError(result))
+                showError(StartingError(result), false)
             }
         }
     }

briar-desktop/src/test/kotlin/org/briarproject/briar/desktop/RunWithTemporaryAccount.kt

 /*
  * Briar Desktop
- * Copyright (C) 2021-2022 The Briar Project
+ * Copyright (C) 2021-2023 The Briar Project
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -17,6 +17,7 @@
  */
 
 @file:Suppress("HardCodedStringLiteral")
+
 package org.briarproject.briar.desktop
 
 import androidx.compose.runtime.LaunchedEffect
@@ -24,6 +25,8 @@ import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.window.application
 import mu.KotlinLogging
 import org.briarproject.bramble.BrambleCoreEagerSingletons
+import org.briarproject.bramble.api.lifecycle.Service
+import org.briarproject.bramble.api.lifecycle.ServiceException
 import org.briarproject.briar.BriarCoreEagerSingletons
 import org.briarproject.briar.desktop.TestUtils.getDataDir
 import org.briarproject.briar.desktop.utils.KLoggerUtils.i
@@ -37,6 +40,7 @@ internal class RunWithTemporaryAccount(
     val createAccount: Boolean = true,
     val login: Boolean = true,
     val makeDirUnwritable: Boolean = false,
+    val addBrokenService: Boolean = false,
     val customization: BriarDesktopTestApp.() -> Unit = {},
 ) {
 
@@ -78,6 +82,16 @@ internal class RunWithTemporaryAccount(
         val lifecycleManager = app.getLifecycleManager()
         val accountManager = app.getAccountManager()
 
+        if (addBrokenService) {
+            lifecycleManager.registerService(object : Service {
+                override fun startService() {
+                    throw ServiceException()
+                }
+
+                override fun stopService() {}
+            })
+        }
+
         if (createAccount) {
             val password = "verySecret123!"
             accountManager.createAccount("alice", password)

briar-desktop/src/test/kotlin/org/briarproject/briar/desktop/TestStartupWithBrokenService.kt

+/*
+ * Briar Desktop
+ * Copyright (C) 2023 The Briar Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.briarproject.briar.desktop
+
+/*
+ * Running this scenario will show an error message after account creation.
+ */
+fun main() = RunWithTemporaryAccount(
+    createAccount = false,
+    addBrokenService = true,
+).run()