From 77042480ae0673e8200fe5fc7a1675282e0b371f Mon Sep 17 00:00:00 2001
From: Maurus Decimus <11444311+mdecimus@users.noreply.github.com>
Date: Thu, 14 May 2026 16:04:19 +0200
Subject: [PATCH] Fix IMAP: `UID FETCH N:*` could miss messages moved into a
 SELECTed mailbox by another connection

---
 CHANGELOG.md                    |  1 +
 crates/imap/src/core/message.rs | 25 +++++++++++++++----------
 tests/src/imap/copy_move.rs     | 25 ++++++++++++++++++++++++-
 3 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b6cdf3e..5e40b49f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ If you are upgrading from v0.16.x, replace the binary (or run `docker pull`). If
 - DAV: `acl-principal-prop-set` REPORT enforced the wrong privilege.
 - JMAP: `Thread/get` did not filter by per-mailbox ACLs on shared accounts.
 - RFC2136 TSIG: regression related to multiplexer.
+- IMAP: `UID FETCH N:*` could miss messages moved into a SELECTed mailbox by another connection.
 
 ## [0.16.5] - 2026-05-11
 
diff --git a/crates/imap/src/core/message.rs b/crates/imap/src/core/message.rs
index 44d7fe66..fa5c3be3 100644
--- a/crates/imap/src/core/message.rs
+++ b/crates/imap/src/core/message.rs
@@ -194,23 +194,28 @@ impl SelectedMailbox {
         if !sequence.is_saved_search() {
             let mut ids = AHashMap::new();
             let state = self.state.lock();
+            let (id_to_imap, uid_max, total_messages) =
+                if let Some(next) = state.next_state.as_ref() {
+                    (
+                        &next.next_state.id_to_imap,
+                        next.next_state.uid_max,
+                        next.next_state.total_messages,
+                    )
+                } else {
+                    (&state.id_to_imap, state.uid_max, state.total_messages)
+                };
 
             if is_uid {
-                let id_to_imap = state
-                    .next_state
-                    .as_ref()
-                    .map(|s| &s.next_state.id_to_imap)
-                    .unwrap_or(&state.id_to_imap);
-                if !state.id_to_imap.is_empty() {
+                if !id_to_imap.is_empty() {
                     for (id, imap_id) in id_to_imap {
-                        if sequence.contains(imap_id.uid, state.uid_max) {
+                        if sequence.contains(imap_id.uid, uid_max) {
                             ids.insert(*id, *imap_id);
                         }
                     }
                 }
-            } else if !state.id_to_imap.is_empty() {
-                for (id, imap_id) in &state.id_to_imap {
-                    if sequence.contains(imap_id.seqnum, state.total_messages as u32) {
+            } else if !id_to_imap.is_empty() {
+                for (id, imap_id) in id_to_imap {
+                    if sequence.contains(imap_id.seqnum, total_messages as u32) {
                         ids.insert(*id, *imap_id);
                     }
                 }
diff --git a/tests/src/imap/copy_move.rs b/tests/src/imap/copy_move.rs
index 2c52f568..a0ed38c5 100644
--- a/tests/src/imap/copy_move.rs
+++ b/tests/src/imap/copy_move.rs
@@ -7,7 +7,7 @@
 use super::{AssertResult, ImapConnection, Type};
 use imap_proto::ResponseType;
 
-pub async fn test(_imap: &mut ImapConnection, imap_check: &mut ImapConnection) {
+pub async fn test(imap: &mut ImapConnection, imap_check: &mut ImapConnection) {
     println!("Running COPY/MOVE tests...");
 
     // Check status
@@ -151,4 +151,27 @@ pub async fn test(_imap: &mut ImapConnection, imap_check: &mut ImapConnection) {
         .assert_contains("\"Burrata al Tartufo\" (UIDNEXT 5 MESSAGES 0 UNSEEN 0 SIZE 0)")
         .assert_contains("\"Scamorza Affumicata\" (UIDNEXT 9 MESSAGES 4 UNSEEN 4 SIZE 5851)")
         .assert_contains("\"INBOX\" (UIDNEXT 11 MESSAGES 10 UNSEEN 10 SIZE 12193)");
+
+    imap_check.send("SELECT \"Burrata al Tartufo\"").await;
+    imap_check.assert_read(Type::Tagged, ResponseType::Ok).await;
+
+    imap.send("SELECT \"Scamorza Affumicata\"").await;
+    imap.assert_read(Type::Tagged, ResponseType::Ok).await;
+    imap.send("UID MOVE 5 \"Burrata al Tartufo\"").await;
+    imap.assert_read(Type::Tagged, ResponseType::Ok)
+        .await
+        .assert_contains("COPYUID");
+
+    imap_check.send("UID FETCH 1:* (UID)").await;
+    imap_check
+        .assert_read(Type::Tagged, ResponseType::Ok)
+        .await
+        .assert_contains("UID 5");
+
+    imap.send("SELECT \"Burrata al Tartufo\"").await;
+    imap.assert_read(Type::Tagged, ResponseType::Ok).await;
+    imap.send("UID MOVE 5 \"Scamorza Affumicata\"").await;
+    imap.assert_read(Type::Tagged, ResponseType::Ok)
+        .await
+        .assert_contains("COPYUID");
 }