This bug was kind of a long one to figure out, as per #1918 documents
the issue had to do with subcommands but the actual adventure in
finding this one was a long one.
The first problem was that Command.cog was for some reason None, which
indicated that a copy was happening somewhere along the way. After some
fiddling I discovered that due to the copies of `Cog.__cog_commands__`
the groups pointed to out-dated versions that got overriden by the new
copies.
The first attempt at fixing this was straightforward -- just remove the
subcommand from the parent and replace it with the newer reference that
we just received. However, this ended up not working due to a strange
mystery where the subcommand being invoked was neither the original
copy nor the new copy residing in `Cog.__cog_commands__`.
Some more investigation later pointed out to me that a copy occurs
during the `Group.copy` stage which calls `Command.copy` for all its
subcommands. After spotting this out I had realised where the
discrepancy comes from. As it turns out, the subcommand copy that was
being invoked was actually a stale one created from `Group.copy`.
The question remained, how come that one was being called? The problem
stemmed from the fact that when the subcommand was copied, the parent
reference pointed to the old parent. Since the old parent was the one
that was getting the new reference, it went practically untouched. This
is because the calling code fetches the child from the parent and the
old parent is nowhere in the call chain.
To fix this issue we needed to update the parent reference, and in
order to do that a temporary lookup table is required pointing to the
latest copies that we have made.
Thus ends a 3.5 hour bug hunting adventure.
This allows for easier "mock" context objects, for those who use
converters as utility functions outside of commands, and it's more
straightforward with the rest of the file.
It turns out that events created in an eval command also cause
the issue described in #1506.
Ensure that events we remove are part of a module as well.
Also performs minor comment maintenance
("x", "first y", "then z") -> ("x", "y", "z")
Use bare raise statement when reraising the exception that occured, and
remove unused exception variables. Also remove a pointless exception
handler in discord.opus.
This adds the following APIs:
* Guild.get_role
This removes the following APIs:
* Guild.role_hierarchy
To compensate for the removed APIs, Guild.roles is now a sorted list
based on hierarchy. The first element will always be the @everyone
role.
This speeds up access at the cost of some memory, theoretically.
Original code by zephyrkul.
This new parsing mode allows for backtracking in case of failure
when a typing.Union[..., NoneType] or a typing.Optional[...] is used.
This means that if a type would fail to parse, the view is undo'd to
a previous state, passing the default parameter to the callback, and
then continuing on the next parameter as if nothing had happened.
