Reverse help_channel_user pairs.

Pairing users to channels was a design flaw,
because the keys didn't get overwritten.
This allowed multiple users to access the dormant command
for the running session of the bot.
Replacing this with a reversed paring fixes both issues
because the cache is overwritten on channel activation.

1 files changed, 4 insertions, 6 deletions

diff --git a/bot/cogs/help_channels.py b/bot/cogs/help_channels.py
index 03bac27a4..dbe7cedc1 100644
--- a/bot/cogs/help_channels.py
+++ b/bot/cogs/help_channels.py
@@ -109,7 +109,7 @@ class HelpChannels(Scheduler, commands.Cog):
         super().__init__()
 
         self.bot = bot
-        self.help_channel_users: t.Dict[discord.User, discord.TextChannel] = {}
+        self.help_channel_users: t.Dict[discord.TextChannel, discord.User] = {}
 
         # Categories
         self.available_category: discord.CategoryChannel = None
@@ -191,7 +191,7 @@ class HelpChannels(Scheduler, commands.Cog):
 
     async def dormant_check(self, ctx: commands.Context) -> bool:
         """Return True if the user started the help channel session or passes the role check."""
-        if self.help_channel_users.get(ctx.author) == ctx.channel:
+        if self.help_channel_users.get(ctx.channel) == ctx.author:
             log.trace(f"{ctx.author} started the help session, passing the check for dormant.")
             return True
 
@@ -563,7 +563,7 @@ class HelpChannels(Scheduler, commands.Cog):
             await self.move_to_in_use(channel)
             await self.revoke_send_permissions(message.author)
             # Add user with channel for dormant check.
-            self.help_channel_users[message.author] = channel
+            self.help_channel_users[channel] = message.author
 
             log.trace(f"Releasing on_message lock for {message.id}.")
 
@@ -622,11 +622,9 @@ class HelpChannels(Scheduler, commands.Cog):
 
     async def reset_send_permissions_for_help_user(self, channel: discord.TextChannel) -> None:
         """Reset send permissions in the Available category for member that started the help session in `channel`."""
-        # Get mapping of channels to users that started the help session in them.
-        channels_to_users = {value: key for key, value in self.help_channel_users.items()}
         log.trace(f"Attempting to find user for help session in #{channel.name} ({channel.id}).")
         try:
-            member: discord.Member = channels_to_users[channel]
+            member = self.help_channel_users[channel]
         except KeyError:
             log.trace(f"Channel #{channel.name} ({channel.id}) not in help session cache, permissions unchanged.")
             return