Merge branch 'develop-2.x' into ver-name-number

app/src/main/java/chat/rocket/android/chatroom/viewmodel/MessageAttachmentViewModel.kt

@@ -7,8 +7,8 @@ data class MessageAttachmentViewModel(
         override val message: Message,
         override val rawData: Message,
         override val messageId: String,
-        var senderName: String,
-        val time: CharSequence,
+        var senderName: String?,
+        val time: CharSequence?,
         val content: CharSequence,
         val isPinned: Boolean,
         override var reactions: List<ReactionViewModel>,

app/src/main/java/chat/rocket/android/chatroom/viewmodel/ViewModelMapper.kt

@@ -103,8 +103,8 @@ class ViewModelMapper @Inject constructor(private val context: Context,
     }
 
     private suspend fun mapMessageAttachment(message: Message, attachment: MessageAttachment): MessageAttachmentViewModel {
-        val attachmentAuthor = attachment.author!!
-        val time = getTime(attachment.timestamp!!)
+        val attachmentAuthor = attachment.author
+        val time = attachment.timestamp?.let { getTime(it) }
         val attachmentText = when (attachment.attachments.orEmpty().firstOrNull()) {
             is ImageAttachment -> context.getString(R.string.msg_preview_photo)
             is VideoAttachment -> context.getString(R.string.msg_preview_video)