From 15d180a785f7edfc5db582e9211d44a7336ef2c4 Mon Sep 17 00:00:00 2001
From: trevor-signal <131492920+trevor-signal@users.noreply.github.com>
Date: Thu, 2 Oct 2025 12:28:35 -0400
Subject: [PATCH] Avoid deadlock when processing deletes and edits concurrently

---
 ts/sql/Server.ts               | 29 ++++++++++++++++++++++++++---
 ts/util/modifyTargetMessage.ts |  4 ++--
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/ts/sql/Server.ts b/ts/sql/Server.ts
index 25078dd7ba..c35dec0d09 100644
--- a/ts/sql/Server.ts
+++ b/ts/sql/Server.ts
@@ -8758,8 +8758,9 @@ function saveEditedMessages(
       alreadyInTransaction: true,
     });
 
-    for (const { conversationId, messageId, readStatus, sentAt } of history) {
-      const [query, params] = sql`
+    try {
+      for (const { conversationId, messageId, readStatus, sentAt } of history) {
+        const [query, params] = sql`
         INSERT INTO edited_messages (
           conversationId,
           messageId,
@@ -8773,7 +8774,29 @@ function saveEditedMessages(
         );
       `;
 
-      db.prepare(query).run(params);
+        db.prepare(query).run(params);
+      }
+    } catch (e) {
+      const [messageExistsQuery, messageExistsParams] = sql`
+        SELECT EXISTS(
+          SELECT 1 FROM messages
+          WHERE messages.id = ${mainMessage.id}
+        );
+      `;
+      const messageExists = db
+        .prepare(messageExistsQuery, {
+          pluck: true,
+        })
+        .get<number>(messageExistsParams);
+
+      if (messageExists !== 1) {
+        logger.warn(
+          'saveEditedMessages: save failed because message does not exist'
+        );
+      } else {
+        // Some other, unknown error
+        throw e;
+      }
     }
   })();
 }
diff --git a/ts/util/modifyTargetMessage.ts b/ts/util/modifyTargetMessage.ts
index 025016152a..a5b551c46f 100644
--- a/ts/util/modifyTargetMessage.ts
+++ b/ts/util/modifyTargetMessage.ts
@@ -365,8 +365,8 @@ export async function modifyTargetMessage(
   if (!isFirstRun && !skipEdits) {
     const edits = Edits.forMessage(message.attributes);
     log.info(`${logId}: ${edits.length} edits in second run`);
-    await Promise.all(
-      edits.map(editAttributes =>
+    edits.map(editAttributes =>
+      drop(
         conversation.queueJob('modifyTargetMessage/edits', () =>
           handleEditMessage(message.attributes, editAttributes)
         )