Some console objects currently do several unique things:
* Delegate waits onto the queue of another object. This is not really a problem for in-process waits, since we can just return the sync object for the delegate. However, it's also unnecessary, adds to the complexity of the server logic, and is one out of one places where this is done.
* Make the wait state dependent on the process. This is difficult to emulate with ntsync and would require creating separate server objects for each process, hacking into duplicate_handle.
* Fail a wait entirely in certain circumstances. This is pretty much impossible to emulate with in-process waits.
Although ntsync has been in development for some time, I have regrettably failed to notice these problems until now.
Fortunately, none of these behaviours happen on modern Windows. Although I/O on unbound handles delegates to the console of the current process, the signaled state does not. As the tests here show, the signaled state of a handle depends on the active console of the process in which the handle was created. If that console no longer exists, the signaled state is no longer updated [with one rather inexplicable exception].
Crucially, in current Windows waits never fail, and the state of an object is the same across all process which hold handles to it. Therefore this patch brings our behaviour to closer match current Windows.
In theory these are fds and should use default_fd_signaled(). However, the points at which the handles are signaled are completely different, and I/O does not trigger console handles to become signaled when it normally would. Therefore for the time being I've kept the code using custom signaled ops.
There is one other oddity related to consoles, which is the existence of console_add_queue(), which seeks to lazily create an input thread when a console is first waited on. This is one out of two places, after this patch, when the wait process is hijacked (the other being message queues). Fortunately this is easy to handle for in-process synchronization objects, by queueing the ioctl from the callback used to retrieve the in-process synchronization object itself.
-- v5: server: Track unbound output signaled state based on its original console. server: Track unbound input signaled state based on its original console. server: Allow waiting on an orphaned screen buffer. server: Use a list of screen buffers per console. server: Fail to create an unbound input/output when there is no console. kernel32/tests: Add more tests for orphaned console handles.