Fix issue of verification banner displayed after logout

vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt

@@ -22,6 +22,6 @@ import org.matrix.android.sdk.api.util.MatrixItem
 sealed class HomeActivityViewEvents : VectorViewEvents {
     data class AskPasswordToInitCrossSigning(val userItem: MatrixItem.UserItem?) : HomeActivityViewEvents()
     data class OnNewSession(val userItem: MatrixItem.UserItem?, val waitForIncomingRequest: Boolean = true) : HomeActivityViewEvents()
-    data class OnCrossSignedInvalidated(val userItem: MatrixItem.UserItem?) : HomeActivityViewEvents()
+    data class OnCrossSignedInvalidated(val userItem: MatrixItem.UserItem) : HomeActivityViewEvents()
     object PromptToEnableSessionPush : HomeActivityViewEvents()
 }

vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt

@@ -78,29 +78,30 @@ class HomeActivityViewModel @AssistedInject constructor(
     }
 
     private fun observeCrossSigningReset() {
-        val safeActiveSession = activeSessionHolder.getSafeActiveSession()
-        val crossSigningService = safeActiveSession
-                ?.cryptoService()
-                ?.crossSigningService()
-        onceTrusted = crossSigningService
-                ?.allPrivateKeysKnown() ?: false
+        val safeActiveSession = activeSessionHolder.getSafeActiveSession() ?: return
+
+        onceTrusted = safeActiveSession
+                .cryptoService()
+                .crossSigningService().allPrivateKeysKnown()
 
         safeActiveSession
-                ?.rx()
-                ?.liveCrossSigningInfo(safeActiveSession.myUserId)
-                ?.subscribe {
+                .rx()
+                .liveCrossSigningInfo(safeActiveSession.myUserId)
+                .subscribe {
                     val isVerified = it.getOrNull()?.isTrusted() ?: false
                     if (!isVerified && onceTrusted) {
                         // cross signing keys have been reset
                         // Tigger a popup to re-verify
-                        _viewEvents.post(
-                                HomeActivityViewEvents.OnCrossSignedInvalidated(
-                                        safeActiveSession.getUser(safeActiveSession.myUserId)?.toMatrixItem()
-                                )
-                        )
+                        // Note: user can be null in case of logout
+                        safeActiveSession.getUser(safeActiveSession.myUserId)
+                                ?.toMatrixItem()
+                                ?.let { user ->
+                                    _viewEvents.post(HomeActivityViewEvents.OnCrossSignedInvalidated(user))
+                                }
                     }
                     onceTrusted = isVerified
-                }?.disposeOnClear()
+                }
+                .disposeOnClear()
     }
 
     private fun observeInitialSync() {