From 3d2c51c14b169b27ce54fe438f55d278db849f04 Mon Sep 17 00:00:00 2001
From: Greyson Parrelli <greyson@signal.org>
Date: Tue, 24 Mar 2026 15:46:39 +0000
Subject: [PATCH] Filter out revisions with mismatched authors during backup
 export.

---
 .../securesms/backup/v2/ArchiveErrorCases.kt        |  4 ++++
 .../backup/v2/exporters/ChatItemArchiveExporter.kt  | 13 +++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
index 3c9b7fff64..baa3dad161 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/ArchiveErrorCases.kt
@@ -194,6 +194,10 @@ object ExportOddities {
     return log(sentTimestamp, "Revisions for this message contained items of a different type than the parent item. Ignoring mismatched revisions.")
   }
 
+  fun mismatchedRevisionAuthor(sentTimestamp: Long): String {
+    return log(sentTimestamp, "Revisions for this message contained items with a different author than the parent item. Ignoring mismatched revisions.")
+  }
+
   fun outgoingMessageWasSentButTimerNotStarted(sentTimestamp: Long): String {
     return log(sentTimestamp, "Outgoing expiring message was sent, but the timer wasn't started. Setting expireStartDate to dateReceived.")
   }
diff --git a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/ChatItemArchiveExporter.kt b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/ChatItemArchiveExporter.kt
index 1a86ed2781..3337c19993 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/ChatItemArchiveExporter.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/ChatItemArchiveExporter.kt
@@ -1741,19 +1741,24 @@ private fun ChatUpdateMessage.canOnlyBeAuthoredBySelf(): Boolean {
 }
 
 private fun List<ChatItem>.repairRevisions(current: ChatItem.Builder): List<ChatItem> {
+  val authorFiltered = this.filter { it.authorId == current.authorId }
+  if (authorFiltered.size != this.size) {
+    Log.w(TAG, ExportOddities.mismatchedRevisionAuthor(current.dateSent))
+  }
+
   return if (current.standardMessage != null) {
-    val filtered = this
+    val filtered = authorFiltered
       .filter { it.standardMessage != null }
       .map { it.withDowngradeVoiceNotes() }
 
-    if (this.size != filtered.size) {
+    if (authorFiltered.size != filtered.size) {
       Log.w(TAG, ExportOddities.mismatchedRevisionHistory(current.dateSent))
     }
 
     filtered
   } else if (current.directStoryReplyMessage != null) {
-    val filtered = this.filter { it.directStoryReplyMessage != null }
-    if (this.size != filtered.size) {
+    val filtered = authorFiltered.filter { it.directStoryReplyMessage != null }
+    if (authorFiltered.size != filtered.size) {
       Log.w(TAG, ExportOddities.mismatchedRevisionHistory(current.dateSent))
     }
     filtered