fix: Don't create 1:1 chat as protected for contact who doesn't prefer to encrypt (#4538)

src/chat.rs

@@ -1999,7 +1999,9 @@ impl ChatIdBlocked {
         }
 
         let peerstate = Peerstate::from_addr(context, contact.get_addr()).await?;
-        let protected = peerstate.map_or(false, |p| p.is_using_verified_key());
+        let protected = peerstate.map_or(false, |p| {
+            p.is_using_verified_key() && p.prefer_encrypt == EncryptPreference::Mutual
+        });
         let smeared_time = create_smeared_timestamp(context);
 
         let chat_id = context

src/tests/verified_chats.rs

@@ -475,6 +475,43 @@ async fn test_break_protection_then_verify_again() -> Result<()> {
     Ok(())
 }
 
+/// Regression test:
+/// - Verify a contact
+/// - The contact stops using DC and sends a message from a classical MUA instead
+/// - Delete the 1:1 chat
+/// - Create a 1:1 chat
+/// - Check that the created chat is not marked as protected
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_create_oneonone_chat_with_former_verified_contact() -> Result<()> {
+    let mut tcm = TestContextManager::new();
+    let alice = tcm.alice().await;
+    let bob = tcm.bob().await;
+    enable_verified_oneonone_chats(&[&alice]).await;
+
+    mark_as_verified(&alice, &bob).await;
+
+    receive_imf(
+        &alice,
+        b"Subject: Message from bob\r\n\
+          From: <bob@example.net>\r\n\
+          To: <alice@example.org>\r\n\
+          Date: Mon, 12 Dec 2022 14:33:39 +0000\r\n\
+          Message-ID: <abcd@example.net>\r\n\
+          \r\n\
+          Heyho!\r\n",
+        false,
+    )
+    .await
+    .unwrap()
+    .unwrap();
+
+    alice.create_chat(&bob).await;
+
+    assert_verified(&alice, &bob, ProtectionStatus::Unprotected).await;
+
+    Ok(())
+}
+
 // ============== Helper Functions ==============
 
 async fn assert_verified(this: &TestContext, other: &TestContext, protected: ProtectionStatus) {