mod_mix_pam: Cleanup of the roster portion

mod_mix_pam/mod_mix_pam.lua

@@ -283,6 +283,24 @@ module:hook("resource-unbind", function(event)
     module:log("debug", "Unbind of not recorded resource %s (%s)", resource, session_jid);
 end);
 
+local function child_with_attrs(stanza, childtag, xmlns, attrs)
+    -- Helper function: Like stanza:childtags, but returns only the first
+    --                  child whose attributes are in attrs (and match the values in attrs).
+    --                  Otherwise, nil is returned.
+    for _, child in ipairs(stanza:childtags(childtag, xmlns)) do
+        for attr_name, attr_value in pairs(attrs) do
+            if child.attrs[attr_name] ~= nil and child.attrs[attr_name] == attr_value then
+                return child;
+            else
+                -- We already now that this is not the child we're looking for
+                break;
+            end
+        end
+    end
+
+    return nil;
+end
+
 module:hook("roster-get", function(event)
     -- NOTE: Currently this requires a patch to make mod_roster emit
     -- the roster-get event
@@ -295,18 +313,14 @@ module:hook("roster-get", function(event)
     module:log("debug", "Annotated roster request received");
 
     -- User requested the roster with an <annotate/>
-    local roster = rm_load_roster(jid.bare(stanza.attr.from));
     local query = event.reply:get_child("query", "jabber:iq:roster");
-    for contact, roster_item in pairs(roster) do
+    for contact, item in pairs(rm_load_roster(jid.bare(stanza.attr.from))) do
-        if roster_item["mix_spid"] ~= nil then
+        if item["mix_spid"] ~= nil then
-            for _, item in ipairs(query:childtags("item")) do
+            local roster_item = child_with_attrs(query, "item", nil, { jid = contact });
-                if item.attr.jid == contact then
+            if roster_item then
-                    item:tag("channel", {
+                roster_item:tag("channel", { xmlns = mix_roster_xmlns, ["participant-id"] = item["mix_spid"] });
-                        xmlns = mix_roster_xmlns,
+            else
-                        ["participant-id"] = roster_item["mix_spid"],
+                module:log("warn", "Could not find %s during annotated roster query!");
-                    });
-                    break;
-                end
             end
         end
     end