Drop empty story replies and misattributed 1:1 messages

Co-authored-by: trevor-signal <131492920+trevor-signal@users.noreply.github.com>

ts/services/backups/export.preload.ts

@@ -1535,6 +1535,20 @@ export class BackupExportStream extends Readable {
       }
     }
 
+    // Drop messages in the wrong 1:1 chat
+    if (conversation && isDirectConversation(conversation.attributes)) {
+      const convoAuthor = this.#getOrPushPrivateRecipient({
+        id: conversation.attributes.id,
+      });
+
+      if (authorId !== me && authorId !== convoAuthor) {
+        log.warn(
+          `${message.sent_at}: Dropping direct message with mismatched author`
+        );
+        return undefined;
+      }
+    }
+
     if (isOutgoing || isIncoming) {
       strictAssert(authorId, 'Incoming/outgoing messages require an author');
     }
@@ -1791,10 +1805,15 @@ export class BackupExportStream extends Readable {
         };
       }
     } else if (message.storyReplyContext || message.storyReaction) {
+      const directStoryReplyMessage = await this.#toDirectStoryReplyMessage({
+        message,
+      });
+      if (!directStoryReplyMessage) {
+        return undefined;
+      }
+
       item = {
-        directStoryReplyMessage: await this.#toDirectStoryReplyMessage({
-          message,
-        }),
+        directStoryReplyMessage,
       };
 
       revisions = await this.#toChatItemRevisions(base, item, message);
@@ -3410,14 +3429,17 @@ export class BackupExportStream extends Readable {
       | 'received_at'
       | 'reactions'
     >;
-  }): Promise<Backups.DirectStoryReplyMessage.Params> {
+  }): Promise<Backups.DirectStoryReplyMessage.Params | undefined> {
     const reactions = this.#getMessageReactions(message);
 
     let reply: Backups.DirectStoryReplyMessage.Params['reply'];
     if (message.storyReaction) {
       reply = { emoji: message.storyReaction.emoji };
-    } else {
+    } else if (message.body) {
       reply = { textReply: await this.#toTextAndLongTextFields(message) };
+    } else {
+      log.warn('Dropping direct story reply message without reaction or body');
+      return undefined;
     }
 
     return { reply, reactions };
@@ -3532,10 +3554,15 @@ export class BackupExportStream extends Readable {
 
           let item: Backups.ChatItem.Params['item'];
           if (parentItem.directStoryReplyMessage) {
-            item = {
-              directStoryReplyMessage: await this.#toDirectStoryReplyMessage({
+            const directStoryReplyMessage =
+              await this.#toDirectStoryReplyMessage({
                 message: history,
-              }),
+              });
+            if (!directStoryReplyMessage) {
+              return undefined;
+            }
+            item = {
+              directStoryReplyMessage,
             };
           } else {
             const standardMessage = await this.#toStandardMessage({

ts/test-electron/backup/bubble_test.preload.ts

@@ -354,6 +354,28 @@ describe('backup/bubble messages', () => {
     );
   });
 
+  it('drops misattributed incoming 1:1 messages', async () => {
+    await asymmetricRoundtripHarness(
+      [
+        {
+          conversationId: contactA.id,
+          id: generateGuid(),
+          type: 'incoming',
+          received_at: 3,
+          received_at_ms: 3,
+          sent_at: 3,
+          sourceServiceId: CONTACT_B,
+          readStatus: ReadStatus.Unread,
+          seenStatus: SeenStatus.Unseen,
+          unidentifiedDeliveryReceived: true,
+          timestamp: 3,
+          body: 'hello',
+        },
+      ],
+      []
+    );
+  });
+
   it('updates incoming messages authored by self to outgoing', async () => {
     const ourConversation = window.ConversationController.get(OUR_ACI);
     strictAssert(ourConversation, 'our conversation exists');
@@ -1263,6 +1285,34 @@ describe('backup/bubble messages', () => {
       await symmetricRoundtripHarness([incomingReply, outgoingReply]);
     });
 
+    it('drops direct story text replies with no body', async () => {
+      strictAssert(ourConversation, 'conversation exists');
+
+      await asymmetricRoundtripHarness(
+        [
+          {
+            conversationId: contactA.id,
+            id: generateGuid(),
+            type: 'incoming',
+            body: '',
+            unidentifiedDeliveryReceived: true,
+            sourceServiceId: CONTACT_A,
+            received_at: 3,
+            received_at_ms: 3,
+            sent_at: 3,
+            timestamp: 3,
+            readStatus: ReadStatus.Read,
+            seenStatus: SeenStatus.Seen,
+            storyReplyContext: {
+              authorAci: OUR_ACI,
+              messageId: '',
+            },
+          },
+        ],
+        []
+      );
+    });
+
     it('does not export group story replies', async () => {
       strictAssert(ourConversation, 'conversations exist');
       strictAssert(group, 'conversations exist');