v3: Inconsistent channel permission values for large guilds between sessions

[Cynosphere]

Every other session ends up with channels in a specific large guild not having permissions (returning 0). The three other smaller guilds the account is in do not have this issue.

I have triaged with another one of my bot accounts in that guild running Dysnomia, targeting that account to check permissions across all channels and it shows correct values.

Additional context: ningen is used

[diamondburned]

How are you getting channel permissions? What's your code?

[Cynosphere]

for _, channel := range guildChannels {
  if channel.Type != discord.GuildText && channel.Type != discord.GuildAnnouncement {
    continue
  }

  private := false

  if channel.ParentID.IsValid() {
    category, err := client.ChannelStore.Channel(channel.ParentID)
    if err == nil {
      perms := discord.CalcOverwrites(*guild, *category, *selfMember)
      private = !perms.Has(discord.PermissionViewChannel)
    }
  }

  if private {
    perms := discord.CalcOverwrites(*guild, channel, *selfMember)
    private = !perms.Has(discord.PermissionViewChannel)
  }

  if private && !withPrivate {
    continue
  }

  // ...
}

[diamondburned]

CalcOverwrites will not try to fetch missing permissions from the given channel. You must use client.Permissions to fetch that. Ideally, CalcOverwrites should not even be used at all.

[Cynosphere]

client.Permissions is consistently returning 0 now when it should be returning 401295005309505 for most of the channels.

[diamondburned]

What does client.Client.Permissions return? (Make sure that client.Client is specifically of type *api.Client.)

[Cynosphere]

*api.Client does not seem to have a Permissions function

[diamondburned]

Sorry, try client.Client.Channel and check its permissions. Also note that these functions don't handle carrying over category permissions.

[Cynosphere]

The permission results seems to be inverted with using !channel.SelfPermissions.Has(discord.PermissionViewChannel), where it thinks the private channels are the ones that the account can see. This is also way too slow for my liking.

I did make my own version of client.Permissions to debug with, and the root cause seems to be guild.Roles being empty.

[diamondburned]

Hmm, so https://github.com/diamondburned/arikawa/blob/v3.3.3/state/state.go#L310 should probably error out when Roles == nil then, which makes sense. (Not the function itself, but this particular branch.)