From 9ec78d145549a66e691b2e137d8cfa43a3c113e4 Mon Sep 17 00:00:00 2001
From: Michael H <michael@michaelhall.tech>
Date: Sat, 4 Jan 2020 14:08:35 -0500
Subject: [PATCH] Fix ctx.clean_prefix for *new* discord behavior (#3249)

* I just love when discord changes important syntax without warning

  - sarcasm approaching dangerous levels

* changelog
---
 changelog.d/3249.bugfix.rst     | 1 +
 redbot/core/commands/context.py | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/3249.bugfix.rst

diff --git a/changelog.d/3249.bugfix.rst b/changelog.d/3249.bugfix.rst
new file mode 100644
index 000000000..9af43d8a6
--- /dev/null
+++ b/changelog.d/3249.bugfix.rst
@@ -0,0 +1 @@
+Fix ``ctx.clean_prefix`` for undocumented changes from discord
diff --git a/redbot/core/commands/context.py b/redbot/core/commands/context.py
index a4e999f3b..d07f73103 100644
--- a/redbot/core/commands/context.py
+++ b/redbot/core/commands/context.py
@@ -1,5 +1,6 @@
 import asyncio
 import contextlib
+import re
 from typing import Iterable, List, Union
 import discord
 from discord.ext import commands
@@ -249,7 +250,8 @@ class Context(commands.Context):
     def clean_prefix(self) -> str:
         """str: The command prefix, but a mention prefix is displayed nicer."""
         me = self.me
-        return self.prefix.replace(me.mention, f"@{me.display_name}")
+        pattern = re.compile(rf"<@!?{me.id}>")
+        return pattern.sub(f"@{me.display_name}", self.prefix)
 
     @property
     def me(self) -> discord.abc.User: