fix multi device attachment issue

app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt

@@ -120,7 +120,7 @@ class Storage(context: Context, helper: SQLCipherOpenHelper) : Database(context,
             val mmsDatabase = DatabaseFactory.getMmsDatabase(context)
             val insertResult = if (message.sender == getUserPublicKey()) {
 
-                val mediaMessage = OutgoingMediaMessage.from(message, targetRecipient, pointerAttachments, quote.orNull(), linkPreviews.orNull().firstOrNull())
+                val mediaMessage = OutgoingMediaMessage.from(message, targetRecipient, pointerAttachments, quote.orNull(), linkPreviews.orNull()?.firstOrNull())
                 mmsDatabase.beginTransaction()
                 mmsDatabase.insertSecureDecryptedMessageOutbox(mediaMessage, message.threadID ?: -1, message.sentTimestamp!!)
             } else {

libsession/src/main/java/org/session/libsession/messaging/messages/visible/Attachment.kt

@@ -3,13 +3,12 @@ package org.session.libsession.messaging.messages.visible
 import android.util.Size
 import android.webkit.MimeTypeMap
 import com.google.protobuf.ByteString
-import org.session.libsession.messaging.sending_receiving.attachments.DatabaseAttachment
+import org.session.libsession.messaging.sending_receiving.attachments.Attachment as SignalAttachment
+import org.session.libsession.messaging.sending_receiving.attachments.PointerAttachment
 import org.session.libsignal.libsignal.util.guava.Optional
 import org.session.libsignal.service.api.messages.SignalServiceAttachmentPointer
 import org.session.libsignal.service.internal.push.SignalServiceProtos
-import org.session.libsignal.utilities.Base64
 import java.io.File
-import org.session.libsession.messaging.sending_receiving.attachments.Attachment as SignalAttachment
 
 class Attachment {
 
@@ -101,9 +100,7 @@ class Attachment {
 
     fun toSignalAttachment(): SignalAttachment? {
         if (!isValid()) return null
-        return DatabaseAttachment(null, 0, false, false, contentType, 0,
-                sizeInBytes?.toLong() ?: 0, if (fileName.isNullOrEmpty()) null else fileName, null, Base64.encodeBytes(key), null, digest, null, kind == Kind.VOICE_MESSAGE,
-                size?.width ?: 0, size?.height ?: 0, false, caption, url)
+        return PointerAttachment.forAttachment((this))
     }
 
     fun toSignalPointer(): SignalServiceAttachmentPointer? {

libsession/src/main/java/org/session/libsession/messaging/sending_receiving/attachments/PointerAttachment.java

@@ -169,4 +169,25 @@ public class PointerAttachment extends Attachment {
             thumbnail != null ? thumbnail.asPointer().getCaption().orNull() : null,
             thumbnail != null ? thumbnail.asPointer().getUrl() : ""));
   }
+
+  /**
+   * Converts a Session Attachment to a Signal Attachment
+   * @param attachment Session Attachment
+   * @return Signal Attachment
+   */
+  public static Attachment forAttachment(org.session.libsession.messaging.messages.visible.Attachment attachment) {
+    return new PointerAttachment(attachment.getContentType(),
+            AttachmentTransferProgress.TRANSFER_PROGRESS_PENDING,
+            attachment.getSizeInBytes(),
+            attachment.getFileName(),
+            null, Base64.encodeBytes(attachment.getKey()),
+            null,
+            attachment.getDigest(),
+            null,
+            attachment.getKind() == org.session.libsession.messaging.messages.visible.Attachment.Kind.VOICE_MESSAGE,
+            attachment.getSize() != null ? attachment.getSize().getWidth() : 0,
+            attachment.getSize() != null ? attachment.getSize().getHeight() : 0,
+            attachment.getCaption(),
+            attachment.getUrl());
+  }
 }