Fix sort order for VoIP events.

event-schemas/schema/v1/m.call.answer

@@ -1,6 +1,7 @@
 {
     "$schema": "http://json-schema.org/draft-04/schema#",
     "type": "object",
+    "description": "This event is sent by the callee when they wish to answer the call.",
     "allOf": [{
         "$ref": "core#/definitions/room_event"
     }],

templating/matrix_templates/sections.py

@@ -63,7 +63,16 @@ class MatrixSections(Sections):
     def render_voip_events(self):
         def filterFn(eventType):
             return eventType.startswith("m.call")
-        return self._render_events(filterFn, sorted)
+        def sortFn(eventTypes):
+            ordering = [
+                "m.call.invite", "m.call.candidates", "m.call.answer",
+                "m.call.hangup"
+            ]
+            rest = [
+                k for k in eventTypes if k not in ordering
+            ]
+            return ordering + rest
+        return self._render_events(filterFn, sortFn)
 
     def render_presence_events(self):
         def filterFn(eventType):