Fix crash with null lastStatus in Conversations (#1042)

app/src/main/java/com/keylesspalace/tusky/components/conversation/ConversationEntity.kt

@@ -182,5 +182,5 @@ fun Conversation.toEntity(accountId: Long) =
                 id,
                 accounts.map { it.toEntity() },
                 unread,
-                lastStatus.toEntity()
+                lastStatus!!.toEntity()
         )

app/src/main/java/com/keylesspalace/tusky/components/conversation/ConversationsRepository.kt

@@ -103,8 +103,9 @@ class ConversationsRepository @Inject constructor(val mastodonApi: MastodonApi,
     }
 
     private fun insertResultIntoDb(accountId: Long, result: List<Conversation>?) {
-        result?.let { conversations ->
-            db.conversationDao().insert(conversations.map { it.toEntity(accountId) })
-        }
+        result?.filter { it.lastStatus != null }
+                ?.map{ it.toEntity(accountId) }
+                ?.let { db.conversationDao().insert(it) }
+
     }
 }

app/src/main/java/com/keylesspalace/tusky/entity/Conversation.kt

@@ -20,6 +20,6 @@ import com.google.gson.annotations.SerializedName
 data class Conversation(
         val id: String,
         val accounts: List<Account>,
-        @SerializedName("last_status") val lastStatus: Status,
+        @SerializedName("last_status") val lastStatus: Status?,  // should never be null, but apparently its possible https://github.com/tuskyapp/Tusky/issues/1038
         val unread: Boolean
 )