Deal with multiple active infractions in database

While there are measures to prevent duplicate active infractions at
the side of the bot, there's no formal restriction at the sid of the
database. This means that it's possible for a user two get two active
ban infractions or two active mute infractions at the same time, for
instance after a manual table edit in Admin.

This leads to an inconsistent state when unmuting/unbanning that user,
as the ban or mute role will be removed on Discord, but only one of the
entries in the database would be set to inactive, while the other(s)
remain active. This means that an unmuted user will be remuted if they
leave and rejoin the Guild.

To handle this, I've inserted code that sets all the infractions to
inactive and cancels all related infraction tasks (in the case of
temporary infractions) when issuing an unban or unmute command. A note
will be added to the mod_log embed to notify us as well.

1 files changed, 50 insertions, 24 deletions

diff --git a/bot/cogs/moderation.py b/bot/cogs/moderation.py
index bec2f98c1..63c0e4417 100644
--- a/bot/cogs/moderation.py
+++ b/bot/cogs/moderation.py
@@ -5,7 +5,7 @@ from datetime import datetime
 from typing import Dict, Union
 
 from discord import (
-    Colour, Embed, Forbidden, Guild, HTTPException, Member, Object, User
+    Colour, Embed, Forbidden, Guild, HTTPException, Member, NotFound, Object, User
 )
 from discord.ext.commands import (
     BadArgument, BadUnionArgument, Bot, Context, command, group
@@ -772,7 +772,7 @@ class Moderation(Scheduler):
 
     @with_role(*MODERATION_ROLES)
     @command()
-    async def unmute(self, ctx: Context, user: Member) -> None:
+    async def unmute(self, ctx: Context, user: UserTypes) -> None:
         """
         Deactivates the active mute infraction for a user.
 
@@ -799,10 +799,10 @@ class Moderation(Scheduler):
                 )
                 return
 
-            infraction = response[0]
-            await self._deactivate_infraction(infraction)
-            if infraction["expires_at"] is not None:
-                self.cancel_expiration(infraction["id"])
+            for infraction in response:
+                await self._deactivate_infraction(infraction)
+                if infraction["expires_at"] is not None:
+                    self.cancel_expiration(infraction["id"])
 
             notified = await self.notify_pardon(
                 user=user,
@@ -822,19 +822,31 @@ class Moderation(Scheduler):
 
             await ctx.send(f"{dm_emoji}:ok_hand: Un-muted {user.mention}.")
 
+            embed_text = textwrap.dedent(
+                f"""
+                    Member: {user.mention} (`{user.id}`)
+                    Actor: {ctx.message.author}
+                    DM: {dm_status}
+                """
+            )
+
+            if len(response) > 1:
+                footer = f"Infraction IDs: {', '.join(str(infr['id']) for infr in response)}"
+                title = "Member unmuted"
+                embed_text += "Note: User had multiple **active** mute infractions in the database."
+            else:
+                infraction = response[0]
+                footer = f"Infraction ID: {infraction['id']}"
+                title = "Member unmuted"
+
             # Send a log message to the mod log
             await self.mod_log.send_log_message(
                 icon_url=Icons.user_unmute,
                 colour=Colour(Colours.soft_green),
-                title="Member unmuted",
+                title=title,
                 thumbnail=user.avatar_url_as(static_format="png"),
-                text=textwrap.dedent(f"""
-                    Member: {user.mention} (`{user.id}`)
-                    Actor: {ctx.message.author}
-                    Intended expiry: {infraction['expires_at']}
-                    DM: {dm_status}
-                """),
-                footer=infraction["id"],
+                text=embed_text,
+                footer=footer,
                 content=log_content
             )
         except Exception:
@@ -873,10 +885,24 @@ class Moderation(Scheduler):
                 )
                 return
 
-            infraction = response[0]
-            await self._deactivate_infraction(infraction)
-            if infraction["expires_at"] is not None:
-                self.cancel_expiration(infraction["id"])
+            for infraction in response:
+                await self._deactivate_infraction(infraction)
+                if infraction["expires_at"] is not None:
+                    self.cancel_expiration(infraction["id"])
+
+            embed_text = textwrap.dedent(
+                f"""
+                    Member: {user.mention} (`{user.id}`)
+                    Actor: {ctx.message.author}
+                """
+            )
+
+            if len(response) > 1:
+                footer = f"Infraction IDs: {', '.join(str(infr['id']) for infr in response)}"
+                embed_text += "Note: User had multiple **active** ban infractions in the database."
+            else:
+                infraction = response[0]
+                footer = f"Infraction ID: {infraction['id']}"
 
             await ctx.send(f":ok_hand: Un-banned {user.mention}.")
 
@@ -886,11 +912,8 @@ class Moderation(Scheduler):
                 colour=Colour(Colours.soft_green),
                 title="Member unbanned",
                 thumbnail=user.avatar_url_as(static_format="png"),
-                text=textwrap.dedent(f"""
-                    Member: {user.mention} (`{user.id}`)
-                    Actor: {ctx.message.author}
-                    Intended expiry: {infraction['expires_at']}
-                """)
+                text=embed_text,
+                footer=footer,
             )
         except Exception:
             log.exception("There was an error removing an infraction.")
@@ -1219,7 +1242,10 @@ class Moderation(Scheduler):
                 log.warning(f"Failed to un-mute user: {user_id} (not found)")
         elif infraction_type == "ban":
             user: Object = Object(user_id)
-            await guild.unban(user)
+            try:
+                await guild.unban(user)
+            except NotFound:
+                log.info(f"Tried to unban user `{user_id}`, but Discord does not have an active ban registered.")
 
         await self.bot.api_client.patch(
             'bot/infractions/' + str(infraction_object['id']),