From e0b922c9493ff5ab01c39af0d1b9fe48d7816e73 Mon Sep 17 00:00:00 2001
From: Draper <27962761+Drapersniper@users.noreply.github.com>
Date: Tue, 7 Jul 2020 19:08:06 +0100
Subject: [PATCH] Make `localwhitelist` check if caller will still be able to
 use bot after changes (#3903)

* Check invokers theoretical perms in localwhitelist add before completing command

* remove unnecessary code

* add check to remove

* ignore bot owner and server owner

* Update core_commands.py

* lets not crash shit
---
 redbot/core/core_commands.py | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/redbot/core/core_commands.py b/redbot/core/core_commands.py
index c39fe73bf..4d16ca4a7 100644
--- a/redbot/core/core_commands.py
+++ b/redbot/core/core_commands.py
@@ -2014,8 +2014,20 @@ class Core(commands.Cog, CoreLogic):
             return
 
         names = [getattr(u_or_r, "name", u_or_r) for u_or_r in users_or_roles]
-        uids = [getattr(u_or_r, "id", u_or_r) for u_or_r in users_or_roles]
-        await self.bot._whiteblacklist_cache.add_to_whitelist(ctx.guild, uids)
+        uids = {getattr(u_or_r, "id", u_or_r) for u_or_r in users_or_roles}
+        if not (ctx.guild.owner == ctx.author or await self.bot.is_owner(ctx.author)):
+            current_whitelist = set(await self.bot._whiteblacklist_cache.get_whitelist(ctx.guild))
+            theoretical_whitelist = current_whitelist.union(uids)
+            ids = {i for i in (ctx.author.id, *(getattr(ctx.author, "_roles", [])))}
+            if ids.isdisjoint(theoretical_whitelist):
+                return await ctx.send(
+                    _(
+                        "I cannot allow you to do this, as it would "
+                        "remove your ability to run commands, "
+                        "please ensure to add yourself to the whitelist first."
+                    )
+                )
+        await self.bot._whiteblacklist_cache.add_to_whitelist(ctx.guild, list(uids))
 
         await ctx.send(_("{names} added to whitelist.").format(names=humanize_list(names)))
 
@@ -2049,8 +2061,19 @@ class Core(commands.Cog, CoreLogic):
             return
 
         names = [getattr(u_or_r, "name", u_or_r) for u_or_r in users_or_roles]
-        uids = [getattr(u_or_r, "id", u_or_r) for u_or_r in users_or_roles]
-        await self.bot._whiteblacklist_cache.remove_from_whitelist(ctx.guild, uids)
+        uids = {getattr(u_or_r, "id", u_or_r) for u_or_r in users_or_roles}
+        if not (ctx.guild.owner == ctx.author or await self.bot.is_owner(ctx.author)):
+            current_whitelist = set(await self.bot._whiteblacklist_cache.get_whitelist(ctx.guild))
+            theoretical_whitelist = current_whitelist - uids
+            ids = {i for i in (ctx.author.id, *(getattr(ctx.author, "_roles", [])))}
+            if theoretical_whitelist and ids.isdisjoint(theoretical_whitelist):
+                return await ctx.send(
+                    _(
+                        "I cannot allow you to do this, as it would "
+                        "remove your ability to run commands."
+                    )
+                )
+        await self.bot._whiteblacklist_cache.remove_from_whitelist(ctx.guild, list(uids))
 
         await ctx.send(
             _("{names} removed from the local whitelist.").format(names=humanize_list(names))