handle RPL_VISIBLEHOST (396) to catch our hostname (maybe username too) changing

src/core_modules/line_handler/__init__.py

@@ -205,6 +205,10 @@ class Module(ModuleManager.BaseModule):
     @utils.hook("raw.received.chghost")
     def chghost(self, event):
         user.chghost(self.events, event)
+    # RPL_VISIBLEHOST, telling us what our hostname (and sometimes username) is
+    @utils.hook("raw.received.396")
+    def handle_396(self, event):
+        core.handle_396(event)
 
     # IRCv3 SETNAME, to change a user's realname
     @utils.hook("raw.received.setname")

src/core_modules/line_handler/core.py

@@ -165,3 +165,9 @@ def handle_433(event):
     _nick_in_use(event["server"])
 def handle_437(event):
     _nick_in_use(event["server"])
+
+def handle_396(event):
+    username, sep, hostname = event["line"][1].rpartition("@")
+    event["server"].hostname = hostname
+    if sep:
+        event["server"].username = username