Fixed sorting of markup entities with the same offsets (#4201)

telethon/extensions/html.py

@@ -167,21 +167,21 @@ def unparse(text: str, entities: Iterable[TypeMessageEntity]) -> str:
 
     text = add_surrogate(text)
     insert_at = []
-    for entity in entities:
+    for i, entity in enumerate(entities):
         s = entity.offset
         e = entity.offset + entity.length
         delimiter = ENTITY_TO_FORMATTER.get(type(entity), None)
         if delimiter:
             if callable(delimiter):
                 delimiter = delimiter(entity, text[s:e])
-            insert_at.append((s, delimiter[0]))
-            insert_at.append((e, delimiter[1]))
+            insert_at.append((s, i, delimiter[0]))
+            insert_at.append((e, len(entities) - i, delimiter[1]))
 
-    insert_at.sort(key=lambda t: t[0])
+    insert_at.sort(key=lambda t: (t[0], t[1]))
     next_escape_bound = len(text)
     while insert_at:
         # Same logic as markdown.py
-        at, what = insert_at.pop()
+        at, _, what = insert_at.pop()
         while within_surrogate(text, at):
             at += 1