Fix #3536: Only use JID in affiliation

add nick if present.

poezio/tabs/muctab.py

@@ -240,7 +240,6 @@ class MucTab(ChatTab):
         """
         Change the affiliation of a nick or JID
         """
-
         if not self.joined:
             return
 
@@ -250,26 +249,45 @@ class MucTab(ChatTab):
                 'The affiliation must be one of ' +
                 ', '.join(valid_affiliations), 'Error')
             return
-        if nick_or_jid in [user.nick for user in self.users]:
-            nick = nick_or_jid
-            jid = None
-        else:
-            nick = None
+        jid = None
+        nick = None
+        for user in self.users:
+            if user.nick == nick_or_jid:
+                jid = user.jid
+                nick = user.nick
+                break
+        if jid is None:
             try:
                 jid = JID(nick_or_jid)
             except InvalidJID:
-                self.core.information('Invalid JID or missing occupant: %s' % nick_or_jid, 'Error')
+                self.core.information(
+                    f'Invalid JID or missing occupant: {nick_or_jid}',
+                    'Error'
+                )
                 return
 
-        async def do_set_affiliation(room: JID, jid: Optional[JID], nick: Optional[str], affiliation: str, reason: str):
+        async def do_set_affiliation(room: JID, jid: JID, nick: Optional[str], affiliation: str, reason: str):
             try:
-                await self.core.xmpp['xep_0045'].set_affiliation(room, jid, nick, affiliation=affiliation, reason=reason)
-            except (IqError, IqTimeout) as e:
+                await self.core.xmpp['xep_0045'].set_affiliation(
+                    room,
+                    nick=nick,
+                    jid=jid,
+                    affiliation=affiliation,
+                    reason=reason
+                )
+                self.core.information(
+                    f"Affiliation of {jid} set to {affiliation} successfully",
+                    "Info"
+                )
+            except (IqError, IqTimeout) as exc:
                 self.core.information(
-                    "Could not set affiliation '%s' for '%s': %s" %
-                    (affiliation, nick_or_jid, e), "Warning")
+                    f"Could not set affiliation '{affiliation}' for '{jid}': {exc}",
+                    "Warning",
+                )
 
-        asyncio.ensure_future(do_set_affiliation(self.jid.bare, jid, nick, affiliation, reason))
+        asyncio.ensure_future(
+            do_set_affiliation(self.jid.bare, jid, nick, affiliation, reason)
+        )
 
     def change_role(self, nick: str, role: str, reason: str = '') -> None:
         """