plugins/muc: Add muc-occupant-groupchat event

  - Plugins can cancel messages before they are broadcast; and while they still have real from jid
  - Use it for subject changes
  - Allows for custom roles (via role_rank)
  - Roles are now checked before subject
  - Removed muc-subject-change event

2 files changed, 36 insertions, 25 deletions

diff --git a/plugins/muc/muc.lib.lua b/plugins/muc/muc.lib.lua
index f2dde69e..35dd9eac 100644
--- a/plugins/muc/muc.lib.lua
+++ b/plugins/muc/muc.lib.lua
@@ -804,26 +804,29 @@ function room_mt:handle_owner_query_set_to_room(origin, stanza)
 end
 
 function room_mt:handle_groupchat_to_room(origin, stanza)
-	-- Prosody has made the decision that messages with <subject/> are exclusively subject changes
-	-- e.g. body will be ignored; even if the subject change was not allowed
-	if stanza:get_child("subject") then
-		return module:fire_event("muc-subject-change", {room = self, origin = origin, stanza = stanza});
-	end
 	local from = stanza.attr.from;
 	local occupant = self:get_occupant_by_real_jid(from);
-	if not occupant then -- not in room
-		origin.send(st.error_reply(stanza, "cancel", "not-acceptable"));
-		return true;
-	elseif occupant.role == "visitor" then
-		origin.send(st.error_reply(stanza, "auth", "forbidden"));
-		return true;
-	end
+	if module:fire_event("muc-occupant-groupchat", {
+		room = self; origin = origin; stanza = stanza; from = from; occupant = occupant;
+	}) then return true; end
 	stanza.attr.from = occupant.nick;
 	self:broadcast_message(stanza);
 	stanza.attr.from = from;
 	return true;
 end
 
+-- Role check
+module:hook("muc-occupant-groupchat", function(event)
+	local role_rank = valid_roles[event.occupant and event.occupant.role or "none"];
+	if role_rank <= valid_roles.none then
+		event.origin.send(st.error_reply(event.stanza, "cancel", "not-acceptable"));
+		return true;
+	elseif role_rank <= valid_roles.visitor then
+		event.origin.send(st.error_reply(event.stanza, "auth", "forbidden"));
+		return true;
+	end
+end, 50);
+
 -- hack - some buggy clients send presence updates to the room rather than their nick
 function room_mt:handle_presence_to_room(origin, stanza)
 	local current_nick = self:get_occupant_jid(stanza.attr.from);
diff --git a/plugins/muc/subject.lib.lua b/plugins/muc/subject.lib.lua
index 34f9a5d4..d1895b4d 100644
--- a/plugins/muc/subject.lib.lua
+++ b/plugins/muc/subject.lib.lua
@@ -9,6 +9,9 @@
 
 local st = require "util.stanza";
 
+local muc_util = module:require "muc/util";
+local valid_roles = muc_util.valid_roles;
+
 local function create_subject_message(from, subject)
 	return st.message({from = from; type = "groupchat"})
 		:tag("subject"):text(subject):up();
@@ -70,20 +73,25 @@ module:hook("muc-occupant-session-new", function(event)
 	send_subject(event.room, event.stanza.attr.from);
 end, 20);
 
--- Role check for subject changes
-module:hook("muc-subject-change", function(event)
-	local room, stanza = event.room, event.stanza;
-	local occupant = room:get_occupant_by_real_jid(stanza.attr.from);
-	if occupant.role == "moderator" or
-		( occupant.role == "participant" and get_changesubject(room) ) then -- and participant
-		local subject = stanza:get_child_text("subject");
-		set_subject(room, occupant.nick, subject);
-		return true;
-	else
-		event.origin.send(st.error_reply(stanza, "auth", "forbidden"));
-		return true;
+-- Prosody has made the decision that messages with <subject/> are exclusively subject changes
+-- e.g. body will be ignored; even if the subject change was not allowed
+module:hook("muc-occupant-groupchat", function(event)
+	local stanza = event.stanza;
+	local subject = stanza:get_child("subject");
+	if subject then
+		local occupant = event.occupant;
+		-- Role check for subject changes
+		local role_rank = valid_roles[occupant and occupant.role or "none"];
+		if role_rank >= valid_roles.moderator or
+			( role_rank >= valid_roles.participant and get_changesubject(event.room) ) then -- and participant
+			set_subject(event.room, occupant.nick, subject:get_text());
+			return true;
+		else
+			event.origin.send(st.error_reply(stanza, "auth", "forbidden"));
+			return true;
+		end
 	end
-end);
+end, 20);
 
 return {
 	get_changesubject = get_changesubject;