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

1 files changed, 21 insertions, 13 deletions

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;