Keep newly created IMAP mailboxes unsubscribed

contrib/testing/README.md

@@ -49,6 +49,9 @@ one-off files in `/tmp`:
   legacy IMAP4 capability contract, STARTTLS with cleartext
   `LOGINDISABLED`, plaintext-pipeline disposal, implicit TLS, LOGIN, and
   shared GSASL PLAIN/LOGIN authentication.
+- `imap-mailbox-check.py` uses disposable quoted hierarchy names to verify
+  LIST/LSUB, Extended LIST and LIST-STATUS plus CREATE, RENAME, SUBSCRIBE,
+  UNSUBSCRIBE, and safe non-empty/depth-first DELETE behavior.
 - `smtp4dev-fixture.py` manages two authenticated, loopback-only external SMTP
   provider fixtures for STARTTLS and implicit TLS plus a TLS-required,
   no-auth relayhost. It validates credentials, captures messages through

contrib/testing/imap-mailbox-check.py

@@ -0,0 +1,201 @@
+#!/usr/bin/env python3
+# This program is free software, licensed under the terms of the GNU GPL.
+# See the Bongo COPYING file for full details.
+# Copyright (c) 2026 Bongo Project contributors
+
+"""Verify live IMAP mailbox listing and lifecycle commands."""
+
+from __future__ import annotations
+
+import os
+import re
+import socket
+import ssl
+import time
+
+
+HOST = os.environ.get("BONGO_TEST_HOST", "127.0.0.1")
+PORT = int(os.environ.get("BONGO_TEST_IMAPS_PORT", "993"))
+TIMEOUT = float(os.environ.get("BONGO_TEST_TIMEOUT", "10"))
+USERNAME = os.environ.get("BONGO_TEST_USER", "test1")
+PASSWORD = os.environ.get("BONGO_TEST_PASSWORD", "")
+TAGGED = re.compile(rb"^([A-Za-z0-9]+) (OK|NO|BAD)(?: .*)?\r\n$")
+
+
+class IMAPCheckError(RuntimeError):
+    """Raised when the live IMAP peer violates the tested contract."""
+
+
+def quote(value: str) -> str:
+    return '"' + value.replace("\\", "\\\\").replace('"', '\\"') + '"'
+
+
+class IMAPConnection:
+    def __init__(self) -> None:
+        raw = socket.create_connection((HOST, PORT), timeout=TIMEOUT)
+        context = ssl.create_default_context()
+        context.check_hostname = False
+        context.verify_mode = ssl.CERT_NONE
+        context.minimum_version = ssl.TLSVersion.TLSv1_2
+        self.socket = context.wrap_socket(raw, server_hostname=HOST)
+        self.socket.settimeout(TIMEOUT)
+        self.reader = self.socket.makefile("rb")
+        self.counter = 0
+        greeting = self.line()
+        if not greeting.startswith(b"* OK "):
+            raise IMAPCheckError(f"unexpected IMAP greeting: {greeting!r}")
+
+    def close(self) -> None:
+        try:
+            self.reader.close()
+        finally:
+            self.socket.close()
+
+    def line(self) -> bytes:
+        line = self.reader.readline(65538)
+        if not line:
+            raise IMAPCheckError("connection closed while waiting for IMAP response")
+        if len(line) > 65536 or not line.endswith(b"\r\n"):
+            raise IMAPCheckError(f"invalid IMAP response line: {line!r}")
+        return line
+
+    def command(
+        self, command: str, expected: tuple[str, ...] = ("OK",)
+    ) -> list[bytes]:
+        self.counter += 1
+        tag = f"M{self.counter:04d}"
+        self.socket.sendall(f"{tag} {command}\r\n".encode("utf-8"))
+        lines: list[bytes] = []
+        while True:
+            line = self.line()
+            match = TAGGED.match(line)
+            if match is not None and match.group(1).decode("ascii") == tag:
+                status = match.group(2).decode("ascii")
+                if status not in expected:
+                    raise IMAPCheckError(
+                        f"{command!r} expected {expected}, received {line!r}"
+                    )
+                return lines + [line]
+            lines.append(line)
+
+
+def contains_mailbox(lines: list[bytes], command: bytes, mailbox: str) -> bool:
+    encoded = quote(mailbox).encode("utf-8")
+    return any(
+        line.upper().startswith(b"* " + command + b" ") and encoded in line
+        for line in lines
+    )
+
+
+def main() -> int:
+    if not PASSWORD:
+        raise IMAPCheckError("BONGO_TEST_PASSWORD must be set")
+    token = f"{os.getpid():x}-{time.time_ns():x}"
+    root = f"Bongo 07 {token}"
+    child = f"{root}/Quoted Child"
+    grandchild = f"{child}/Grandchild"
+    renamed = f"{root} Renamed"
+    renamed_child = f"{renamed}/Quoted Child"
+    renamed_grandchild = f"{renamed_child}/Grandchild"
+    client = IMAPConnection()
+    existing: list[str] = []
+    subscribed: set[str] = set()
+    try:
+        client.command(f"LOGIN {quote(USERNAME)} {quote(PASSWORD)}")
+        delimiter = client.command('LIST "" ""')
+        if not any(b'* LIST (' in line and b'"/"' in line for line in delimiter):
+            raise IMAPCheckError(f"LIST delimiter response missing: {delimiter!r}")
+
+        for mailbox in (root, child, grandchild):
+            client.command(f"CREATE {quote(mailbox)}")
+            existing.append(mailbox)
+        for mailbox in (root, child):
+            client.command(f"SUBSCRIBE {quote(mailbox)}")
+            subscribed.add(mailbox)
+
+        one_level = client.command(f'LIST "" {quote(root + "/%")}')
+        if not contains_mailbox(one_level, b"LIST", child):
+            raise IMAPCheckError("LIST % omitted the direct child")
+        if contains_mailbox(one_level, b"LIST", grandchild):
+            raise IMAPCheckError("LIST % incorrectly returned a grandchild")
+
+        parent_lsub = client.command(f'LSUB "" {quote(root)}')
+        if not contains_mailbox(parent_lsub, b"LSUB", root):
+            raise IMAPCheckError("LSUB omitted the subscribed parent")
+        lsub = client.command(f'LSUB "" {quote(root + "/*")}')
+        if not contains_mailbox(lsub, b"LSUB", child):
+            raise IMAPCheckError("LSUB omitted the subscribed child")
+        if contains_mailbox(lsub, b"LSUB", grandchild):
+            raise IMAPCheckError(
+                f"LSUB returned an unsubscribed grandchild: {lsub!r}"
+            )
+
+        extended = client.command(
+            f'LIST (SUBSCRIBED) "" {quote(root + "/*")} '
+            "RETURN (CHILDREN STATUS (MESSAGES UNSEEN SIZE))"
+        )
+        if not contains_mailbox(extended, b"LIST", child):
+            raise IMAPCheckError("extended LIST omitted the subscribed child")
+        child_lines = [
+            line for line in extended if quote(child).encode("utf-8") in line
+        ]
+        if not any(b"\\Subscribed" in line and b"\\HasChildren" in line
+                   for line in child_lines):
+            raise IMAPCheckError(
+                f"extended LIST attributes missing: {child_lines!r}"
+            )
+        if not any(
+            line.upper().startswith(b"* STATUS ")
+            and quote(child).encode("utf-8") in line
+            and all(item in line.upper() for item in (b"MESSAGES", b"UNSEEN", b"SIZE"))
+            for line in extended
+        ):
+            raise IMAPCheckError(f"LIST-STATUS response missing: {extended!r}")
+
+        client.command(f"RENAME {quote(root)} {quote(renamed)}")
+        existing[:] = [renamed, renamed_child, renamed_grandchild]
+        subscribed = {renamed, renamed_child}
+        renamed_list = client.command(f'LIST "" {quote(renamed + "/*")}')
+        if not contains_mailbox(renamed_list, b"LIST", renamed_child):
+            raise IMAPCheckError("RENAME did not preserve the child hierarchy")
+        if not contains_mailbox(renamed_list, b"LIST", renamed_grandchild):
+            raise IMAPCheckError("RENAME did not preserve the grandchild hierarchy")
+
+        client.command(f"UNSUBSCRIBE {quote(renamed_child)}")
+        subscribed.discard(renamed_child)
+        after_unsubscribe = client.command(f'LSUB "" {quote(renamed + "/*")}')
+        if contains_mailbox(after_unsubscribe, b"LSUB", renamed_child):
+            raise IMAPCheckError("UNSUBSCRIBE left the child in LSUB")
+
+        client.command(f"DELETE {quote(renamed)}", expected=("NO",))
+        for mailbox in (renamed_grandchild, renamed_child, renamed):
+            client.command(f"DELETE {quote(mailbox)}")
+            existing.remove(mailbox)
+        subscribed.clear()
+        client.command("LOGOUT")
+    finally:
+        for mailbox in sorted(subscribed, key=len, reverse=True):
+            try:
+                client.command(f"UNSUBSCRIBE {quote(mailbox)}", ("OK", "NO"))
+            except (IMAPCheckError, OSError):
+                pass
+        for mailbox in sorted(existing, key=len, reverse=True):
+            try:
+                client.command(f"DELETE {quote(mailbox)}", ("OK", "NO"))
+            except (IMAPCheckError, OSError):
+                pass
+        client.close()
+
+    print(
+        "IMAP-05/06 PASS "
+        f"host={HOST}:{PORT} delimiter=/ hierarchy=quoted "
+        "list=percent/star lsub=subscribed-only "
+        "extended=subscribed/children/list-status "
+        "lifecycle=create/rename/sub/unsub/delete nonempty-delete=NO "
+        "cleanup=yes"
+    )
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

src/agents/imap/imapd.c

@@ -1283,7 +1283,10 @@ FolderHierarchyCreate(ImapSession *session, char *folderPathUtf8)
             if (NMAPSendCommandF(session->store.conn, "CREATE /mail/%s\r\n", folderPathUtf8) != -1) {
                 ccode = NMAPReadResponse(session->store.conn, NULL, 0, 0);
                 if (ccode == 1000) {
-                    if (NMAPSendCommandF(session->store.conn, "FLAG /mail/%s +%u\r\n", folderPathUtf8, STORE_COLLECTION_FLAG_HIERARCHY_ONLY) != -1) {
+                    if (NMAPSendCommandF(
+                            session->store.conn, "FLAG /mail/%s %u\r\n",
+                            folderPathUtf8,
+                            (unsigned int)IMAPCreateMailboxFlags(0, TRUE)) != -1) {
                         ccode = NMAPReadResponse(session->store.conn, NULL, 0, 0);
                         if (ccode == 1000) {
                             *ptr = '/';
@@ -1383,7 +1386,7 @@ ImapCommandCreate(void *param)
         /* this folder is just hierarchy.  Make it a real folder */
         folder->flags &= ~(STORE_COLLECTION_FLAG_HIERARCHY_ONLY |
                            STORE_COLLECTION_FLAG_SPECIAL_USE_MASK);
-        folder->flags |= specialUseFlags;
+        folder->flags |= IMAPCreateMailboxFlags(specialUseFlags, FALSE);
         if (NMAPSendCommandF(session->store.conn, "FLAG /mail/%s %lu\r\n",
                              pathUtf8, folder->flags) == -1) {
             MemFree(pathUtf8);
@@ -1405,14 +1408,10 @@ ImapCommandCreate(void *param)
         return(SendError(session->client.conn, session->command.tag, "CREATE", ccode));
     }
     
-    if (specialUseFlags != 0) {
-        ccode = NMAPSendCommandF(session->store.conn,
-                                 "CREATE \"/mail/%s\" 0 %u\r\n",
-                                 pathUtf8, (unsigned int)specialUseFlags);
-    } else {
-        ccode = NMAPSendCommandF(session->store.conn,
-                                 "CREATE \"/mail/%s\"\r\n", pathUtf8);
-    }
+    ccode = NMAPSendCommandF(
+        session->store.conn, "CREATE \"/mail/%s\" 0 %u\r\n",
+        pathUtf8,
+        (unsigned int)IMAPCreateMailboxFlags(specialUseFlags, FALSE));
     if (ccode == -1) {
         MemFree(pathUtf8);
         return(SendError(session->client.conn, session->command.tag, "CREATE", STATUS_NMAP_COMM_ERROR));

src/agents/imap/special-use.c

@@ -127,3 +127,13 @@ IMAPSpecialUseFormat(uint32_t flags, char *buffer, size_t buffer_size)
     }
     return length;
 }
+
+uint32_t
+IMAPCreateMailboxFlags(uint32_t special_use_flags, int hierarchy_only)
+{
+    uint32_t flags = special_use_flags |
+                     STORE_COLLECTION_FLAG_NON_SUBSCRIBED;
+
+    if (hierarchy_only) flags |= STORE_COLLECTION_FLAG_HIERARCHY_ONLY;
+    return flags;
+}

src/agents/imap/special-use.h

@@ -27,5 +27,7 @@
 
 int IMAPSpecialUseParseCreateOptions(const char *text, uint32_t *flags);
 size_t IMAPSpecialUseFormat(uint32_t flags, char *buffer, size_t buffer_size);
+uint32_t IMAPCreateMailboxFlags(uint32_t special_use_flags,
+                                int hierarchy_only);
 
 #endif

src/agents/imap/tests/special-use-test.c

@@ -50,5 +50,14 @@ main(void)
     assert(buffer[0] == '\0');
     assert(IMAPSpecialUseFormat(flags, buffer, 4) == 0);
     assert(buffer[0] == '\0');
+
+    assert(IMAPCreateMailboxFlags(0, 0) ==
+           STORE_COLLECTION_FLAG_NON_SUBSCRIBED);
+    assert(IMAPCreateMailboxFlags(STORE_COLLECTION_FLAG_SPECIAL_SENT, 0) ==
+           (STORE_COLLECTION_FLAG_NON_SUBSCRIBED |
+            STORE_COLLECTION_FLAG_SPECIAL_SENT));
+    assert(IMAPCreateMailboxFlags(0, 1) ==
+           (STORE_COLLECTION_FLAG_NON_SUBSCRIBED |
+            STORE_COLLECTION_FLAG_HIERARCHY_ONLY));
     return 0;
 }