Always allow users sign out

- Updates the dialog with a more helpful error message for the user, letting them know what happens if they logout without informing the homeserver.

changelog.d/4855.bugfix

@@ -0,0 +1 @@
+Fix: Allow users to sign out even if the sign out request fails.

library/ui-strings/src/main/res/values/strings.xml

@@ -328,6 +328,9 @@
     <string name="backup">Back up</string>
     <string name="sign_out_bottom_sheet_will_lose_secure_messages">You’ll lose access to your encrypted messages unless you back up your keys before signing out.</string>
 
+    <string name="sign_out_failed_dialog_message">Cannot reach the homeserver. If you sign out anyway, this device will not be erased from your device list, you may want to remove it using another client.</string>
+    <string name="sign_out_anyway">Sign out anyway</string>
+
     <!-- splash screen accessibility -->
     <string name="loading">Loading…</string>
 

vector/src/main/java/im/vector/app/features/MainActivity.kt

@@ -252,13 +252,10 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
                     try {
                         session.signOutService().signOut(!args.isUserLoggedOut)
                     } catch (failure: Throwable) {
-                        displayError(failure)
+                        displaySignOutFailedDialog(onboardingStore)
                         return@launch
                     }
-                    Timber.w("SIGN_OUT: success, start app")
-                    activeSessionHolder.clearActiveSession()
-                    doLocalCleanup(clearPreferences = true, onboardingStore)
-                    startNextActivityAndFinish()
+                    completeSignout(onboardingStore)
                 }
             }
             args.clearCache -> {
@@ -272,6 +269,15 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
         }
     }
 
+    private fun completeSignout(onboardingStore: VectorSessionStore) {
+        lifecycleScope.launch {
+            Timber.w("SIGN_OUT: success, start app")
+            activeSessionHolder.clearActiveSession()
+            doLocalCleanup(clearPreferences = true, onboardingStore)
+            startNextActivityAndFinish()
+        }
+    }
+
     override fun handleInvalidToken(globalError: GlobalError.InvalidToken) {
         // No op here
         Timber.w("Ignoring invalid token global error")
@@ -299,12 +305,13 @@ class MainActivity : VectorBaseActivity<ActivityMainBinding>(), UnlockedActivity
         }
     }
 
-    private fun displayError(failure: Throwable) {
+    private fun displaySignOutFailedDialog(onboardingStore: VectorSessionStore) {
         if (lifecycle.currentState.isAtLeast(Lifecycle.State.RESUMED)) {
             MaterialAlertDialogBuilder(this)
                     .setTitle(R.string.dialog_title_error)
-                    .setMessage(errorFormatter.toHumanReadable(failure))
-                    .setPositiveButton(R.string.global_retry) { _, _ -> doCleanUp() }
+                    .setMessage(R.string.sign_out_failed_dialog_message)
+                    .setPositiveButton(R.string.sign_out_anyway) { _, _ -> completeSignout(onboardingStore) }
+                    .setNeutralButton(R.string.global_retry) { _, _ -> doCleanUp() }
                     .setNegativeButton(R.string.action_cancel) { _, _ -> startNextActivityAndFinish(ignoreClearCredentials = true) }
                     .setCancelable(false)
                     .show()