From c5d357ca286908bc60c76e5456bac96968ae9ae5 Mon Sep 17 00:00:00 2001
From: mdecimus <11444311+mdecimus@users.noreply.github.com>
Date: Thu, 18 Dec 2025 16:04:06 +0100
Subject: [PATCH] IMAP: Fix shared folder double nesting (test suite credits to
 @ochnygosch) (fixes #2358 closes #2525)

---
 crates/imap/src/op/create.rs | 11 ++++++---
 tests/src/imap/mailbox.rs    | 47 ++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/crates/imap/src/op/create.rs b/crates/imap/src/op/create.rs
index 79a32f09..272a4e07 100644
--- a/crates/imap/src/op/create.rs
+++ b/crates/imap/src/op/create.rs
@@ -177,7 +177,7 @@ impl<T: SessionStream> SessionData<T> {
         let mut parent_mailbox_name = None;
         let (account_id, path) = {
             let mailboxes = self.mailboxes.lock();
-            let (account, full_path) =
+            let (account, full_path, prefix) =
                 if path.first() == Some(&self.server.core.jmap.shared_folder.as_str()) {
                     // Shared Folders/<username>/<folder>
                     if path.len() < 3 {
@@ -201,7 +201,7 @@ impl<T: SessionStream> SessionData<T> {
                         .skip(1)
                         .find(|account| account.prefix == prefix)
                     {
-                        (account, full_path)
+                        (account, full_path, prefix)
                     } else {
                         #[allow(clippy::unnecessary_literal_unwrap)]
                         return Err(trc::ImapEvent::Error.into_err().details(format!(
@@ -215,7 +215,7 @@ impl<T: SessionStream> SessionData<T> {
                         *root = "INBOX";
                     }
 
-                    (account, path.join("/"))
+                    (account, path.join("/"), None)
                 } else {
                     return Err(trc::ImapEvent::Error
                         .into_err()
@@ -241,6 +241,11 @@ impl<T: SessionStream> SessionData<T> {
                             parent_mailbox_id = mailbox_id.into();
                             parent_mailbox_name = mailbox_name.into();
                             break;
+                        } else if prefix
+                            .as_ref()
+                            .is_some_and(|prefix| prefix == &mailbox_name)
+                        {
+                            break;
                         } else {
                             create_path.push(path.pop().unwrap());
                         }
diff --git a/tests/src/imap/mailbox.rs b/tests/src/imap/mailbox.rs
index 06cf55de..1d732a21 100644
--- a/tests/src/imap/mailbox.rs
+++ b/tests/src/imap/mailbox.rs
@@ -324,6 +324,53 @@ pub async fn test(mut imap: &mut ImapConnection, mut imap_check: &mut ImapConnec
     // Restore Trash folder's original name
     imap.send("RENAME \"Recycle Bin\" \"Deleted Items\"").await;
     imap.assert_read(Type::Tagged, ResponseType::Ok).await;
+
+    // Shared folder creation tests
+    let mut imap_jane = ImapConnection::connect(b"_z ").await;
+    imap_jane
+        .authenticate("jane.smith@example.com", "secret")
+        .await;
+    imap_jane
+        .send("CREATE \"Shared Folders/support@example.com/INBOX/Test\"")
+        .await;
+    imap_jane.assert_read(Type::Tagged, ResponseType::Ok).await;
+
+    imap_jane
+        .send("CREATE \"Shared Folders/support@example.com/Test\"")
+        .await;
+    imap_jane.assert_read(Type::Tagged, ResponseType::Ok).await;
+
+    imap_jane
+        .send("CREATE \"Shared Folders/support@example.com/Test/TestSubfolder\"")
+        .await;
+    imap_jane.assert_read(Type::Tagged, ResponseType::Ok).await;
+    imap_jane.send("LIST \"\" \"*\"").await;
+    imap_jane
+        .assert_read(Type::Tagged, ResponseType::Ok)
+        .await
+        .assert_folders(
+            [
+                ("INBOX", [""]),
+                ("Deleted Items", [""]),
+                ("Drafts", [""]),
+                ("Junk Mail", [""]),
+                ("Sent Items", [""]),
+                ("Shared Folders", [""]),
+                ("Shared Folders/support@example.com", [""]),
+                ("Shared Folders/support@example.com/Deleted Items", [""]),
+                ("Shared Folders/support@example.com/Drafts", [""]),
+                ("Shared Folders/support@example.com/INBOX", [""]),
+                ("Shared Folders/support@example.com/INBOX/Test", [""]),
+                ("Shared Folders/support@example.com/Junk Mail", [""]),
+                ("Shared Folders/support@example.com/Sent Items", [""]),
+                ("Shared Folders/support@example.com/Test", [""]),
+                (
+                    "Shared Folders/support@example.com/Test/TestSubfolder",
+                    [""],
+                ),
+            ],
+            true,
+        );
 }
 
 fn mailbox_matches_pattern() {