Fix missing attachment placeholder (#1777)

Author: SessionHero01

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/messages/MessageFormatter.kt

@@ -32,6 +32,7 @@ import org.thoughtcrime.securesms.auth.LoginStateRepository
 import org.thoughtcrime.securesms.database.RecipientRepository
 import org.thoughtcrime.securesms.database.model.GroupThreadStatus
 import org.thoughtcrime.securesms.database.model.MessageRecord
+import org.thoughtcrime.securesms.database.model.MmsMessageRecord
 import org.thoughtcrime.securesms.database.model.ThreadRecord
 import org.thoughtcrime.securesms.database.model.content.DisappearingMessageUpdate
 import org.thoughtcrime.securesms.ui.getSubbedCharSequence
@@ -176,6 +177,22 @@ class MessageFormatter @Inject constructor(
                 context.getString(R.string.communityInvitation)
             }
 
+            // Show a placeholder text for messages with attachments
+            lastMessage is MmsMessageRecord -> {
+                val placeholderBody = lastMessage.slideDeck.body
+                val messageBody = lastMessage.body
+
+                if (placeholderBody.isNotBlank()) {
+                    if (messageBody.isNotBlank()) {
+                        "$placeholderBody: $messageBody"
+                    } else {
+                        placeholderBody
+                    }
+                } else {
+                    messageBody
+                }
+            }
+
             else -> {
                 val text = formatMessageBody(
                     context = context,