From 72bfae9448b27d76a74f7213f59f49965ac74ba8 Mon Sep 17 00:00:00 2001
From: iequidoo <dgreshilov@gmail.com>
Date: Tue, 26 Mar 2024 22:06:51 -0300
Subject: [PATCH] fix: Keep tombstones for two days before deleting (#3685)

This is a way to prevent redownloading locally deleted messages. Otherwise if a message is deleted
quickly after sending and `bcc_self` is configured, the BCC copy is downloaded and appears as a new
message as it happens for messages sent from another device.
---
 python/tests/test_0_complex_or_slow.py | 14 ++++++++++++++
 src/sql.rs                             |  7 +++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/python/tests/test_0_complex_or_slow.py b/python/tests/test_0_complex_or_slow.py
index 4ee773912..fbd5738f2 100644
--- a/python/tests/test_0_complex_or_slow.py
+++ b/python/tests/test_0_complex_or_slow.py
@@ -1,4 +1,5 @@
 import sys
+import time
 
 import pytest
 import deltachat as dc
@@ -675,3 +676,16 @@ def test_verified_group_vs_delete_server_after(acfactory, tmp_path, lp):
     assert msg_in.chat == chat2_offl
     assert msg_in.get_sender_contact().addr == ac2.get_config("addr")
     assert ac2_offl_ac1_contact.is_verified()
+
+
+def test_deleted_msgs_dont_reappear(acfactory):
+    ac1 = acfactory.new_online_configuring_account()
+    acfactory.bring_accounts_online()
+    ac1.set_config("bcc_self", "1")
+    chat = ac1.get_self_contact().create_chat()
+    msg = chat.send_text("hello")
+    ac1._evtracker.get_matching("DC_EVENT_SMTP_MESSAGE_SENT")
+    ac1.delete_messages([msg])
+    ac1._evtracker.get_matching("DC_EVENT_MSG_DELETED")
+    time.sleep(5)
+    assert len(chat.get_messages()) == 0
diff --git a/src/sql.rs b/src/sql.rs
index 16409d92e..f85213851 100644
--- a/src/sql.rs
+++ b/src/sql.rs
@@ -990,16 +990,19 @@ async fn maybe_add_from_param(
     Ok(())
 }
 
-/// Removes from the database locally deleted messages that also don't
+/// Removes from the database stale locally deleted messages that also don't
 /// have a server UID.
 async fn prune_tombstones(sql: &Sql) -> Result<()> {
+    // Keep tombstones for the last two days to prevent redownloading locally deleted messages.
+    let timestamp_max = time().saturating_sub(2 * 24 * 3600);
     sql.execute(
         "DELETE FROM msgs
          WHERE chat_id=?
+         AND timestamp<=?
          AND NOT EXISTS (
          SELECT * FROM imap WHERE msgs.rfc724_mid=rfc724_mid AND target!=''
          )",
-        (DC_CHAT_ID_TRASH,),
+        (DC_CHAT_ID_TRASH, timestamp_max),
     )
     .await?;
     Ok(())