From c438554f9ae840a0e2788e6c7ee097bce258b8f4 Mon Sep 17 00:00:00 2001
From: Stephen Paul Weber <singpolyma@singpolyma.net>
Date: Wed, 23 Sep 2026 21:59:20 -0500
Subject: [PATCH] Ignore nick change when there is a configured nick

The user has configured their nick and that's what we should use. If
they send a nick change, just reply letting them know what their nick
actually is.
---
 src/bridge/bridge.cpp                         | 23 ++++++++++++++++
 .../scenarios/nick_change_when_configured.py  | 26 +++++++++++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 tests/end_to_end/scenarios/nick_change_when_configured.py

diff --git a/src/bridge/bridge.cpp b/src/bridge/bridge.cpp
index daf297b..fcf3dcc 100644
--- a/src/bridge/bridge.cpp
+++ b/src/bridge/bridge.cpp
@@ -599,6 +599,29 @@ void Bridge::send_irc_nick_change(const Iid& iid, const std::string& new_nick, c
   if (new_nick == irc->get_own_nick())
     return;
 
+#ifdef USE_DATABASE
+  auto soptions = Database::get_irc_server_options(this->get_bare_jid(), iid.get_server());
+  const auto& db_nick = soptions.col<Database::Nick>();
+  if (!db_nick.empty())
+    {
+      IrcChannel* channel = irc->get_channel(iid.get_local());
+      const IrcUser* self = channel ? channel->get_self() : nullptr;
+      // Send presence 110+210 to let them know the nick we're actually using
+      if (self)
+        {
+          this->send_user_join(iid.get_server(), iid.get_local(), self,
+                               self->get_most_significant_mode(irc->get_sorted_user_modes()),
+                               true, requesting_resource);
+        }
+      else
+        {
+          IrcUser user(irc->get_own_nick());
+          this->send_user_join(iid.get_server(), iid.get_local(), &user, '\0', true, requesting_resource);
+        }
+      return;
+    }
+#endif
+
   irc->send_nick_command(new_nick);
 }
 
diff --git a/tests/end_to_end/scenarios/nick_change_when_configured.py b/tests/end_to_end/scenarios/nick_change_when_configured.py
new file mode 100644
index 0000000..15dc38a
--- /dev/null
+++ b/tests/end_to_end/scenarios/nick_change_when_configured.py
@@ -0,0 +1,26 @@
+from scenarios import *
+
+scenario = (
+    send_stanza("<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/{nick_one}' ><x xmlns='http://jabber.org/protocol/muc'/></presence>"),
+    sequences.connection(),
+    expect_stanza("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@role='moderator']",
+                  "/presence/muc_user:x/muc_user:status[@code='110']"),
+    expect_stanza("/message[@from='#foo%{irc_server_one}'][@type='groupchat']/subject[not(text())]"),
+
+    # Configure a nickname in the database for this server
+    send_stanza("<iq type='set' id='conf1' from='{jid_one}/{resource_one}' to='{irc_server_one}'><command xmlns='http://jabber.org/protocol/commands' node='configure' action='execute' /></iq>"),
+    expect_stanza("/iq[@type='result']",
+                  after = save_value("sessionid", extract_attribute("/iq[@type='result']/commands:command[@node='configure']", "sessionid"))),
+    send_stanza("<iq type='set' id='conf2' from='{jid_one}/{resource_one}' to='{irc_server_one}'>"
+                "<command xmlns='http://jabber.org/protocol/commands' node='configure' sessionid='{sessionid}' action='complete'>"
+                "<x xmlns='jabber:x:data' type='submit'>"
+                "<field var='nick'><value>{nick_one}</value></field>"
+                "</x></command></iq>"),
+    expect_stanza("/iq[@type='result']/commands:command[@node='configure'][@status='completed']/commands:note[@type='info'][text()='Configuration successfully applied.']"),
+
+    # Now with a DB nick configured, attempt to change nick: should reply with 110 + 210 presence rewriting to DB nick
+    send_stanza("<presence from='{jid_one}/{resource_one}' to='#foo%{irc_server_one}/SomeOtherNick' />"),
+    expect_stanza("/presence[@to='{jid_one}/{resource_one}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@role='moderator']",
+                  "/presence/muc_user:x/muc_user:status[@code='110']",
+                  "/presence/muc_user:x/muc_user:status[@code='210']"),
+)