From 794ac0c95454eadce0e77632e0880c0bb8229292 Mon Sep 17 00:00:00 2001
From: Ryan ZHAO <ryanzhaors@qq.com>
Date: Wed, 19 Aug 2020 11:17:11 +1000
Subject: [PATCH] fix crash that link preview attachment is might be null

---
 .../src/ViewControllers/ConversationView/ConversationViewItem.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
index 0228d8f10..5e70d44f3 100644
--- a/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
+++ b/Signal/src/ViewControllers/ConversationView/ConversationViewItem.m
@@ -705,7 +705,7 @@ NSString *NSStringForOWSMessageCellType(OWSMessageCellType cellType)
 
     if (self.hasBodyText && message.linkPreview) {
         self.linkPreview = message.linkPreview;
-        if (message.linkPreview.imageAttachmentId.length > 0) {
+        if (message.linkPreview.imageAttachmentId && message.linkPreview.imageAttachmentId.length) {
             TSAttachment *_Nullable linkPreviewAttachment =
                 [TSAttachment fetchObjectWithUniqueID:message.linkPreview.imageAttachmentId transaction:transaction];
             if (!linkPreviewAttachment) {