client side redirection to a different IP/port hangs

[soliton-]

When wesnothd redirects clients to a different IP/port wesnoth gets stuck.

The server logs the redirection and also still successfully redirects older clients. Must be something introduced since 1.13.10.

[stevecotton]

Is the server redirecting to a different place based on the version number?

On Sunday evening I saw this, but reverting b6a5341 ("Pre-release version bump") made it connect to the dev server again. I assumed it was simply being redirected to a server instance that hadn't been compiled yet.

[jyrkive]

Call stack when it's stuck:

 	ntdll.dll!_NtDelayExecution@8�()	Unknown
 	KernelBase.dll!SleepEx()	Unknown
 	KernelBase.dll!_Sleep@4�()	Unknown
 	SDL2.dll!6c817502()	Unknown
 	[Frames below may be incorrect and/or missing, no symbols loaded for SDL2.dll]	
>	wesnoth.exe!wesnothd_connection::wait_and_receive_data({...}) Line 397	C++
 	wesnoth.exe!`anonymous namespace'::open_connection({...}) Line 109	C++
 	wesnoth.exe!mp::start_client::__l6::<lambda>() Line 597	C++
 	wesnoth.exe!std::_Callable_obj<void <lambda>(void),0>::_ApplyX<void>() Line 284	C++
 	wesnoth.exe!std::_Func_impl<std::_Callable_obj<void <lambda>(void),0>,std::allocator<std::_Func_class<void> >,void>::_Do_call() Line 229	C++
 	wesnoth.exe!std::_Func_class<void>::operator()() Line 316	C++
 	wesnoth.exe!gui2::dialogs::loading_screen::pre_show::__l8::<lambda>() Line 116	C++
 	wesnoth.exe!boost::detail::thread_data<void <lambda>(void) >::run() Line 117	C++
 	wesnoth.exe!boost::`anonymous namespace'::thread_start_function(0x08c0c208) Line 298	C++
 	msvcr120d.dll!_callthreadstartex() Line 376	C
 	msvcr120d.dll!_threadstartex(0x0dc89f48) Line 359	C
 	kernel32.dll!@BaseThreadInitThunk@12�()	Unknown
 	ntdll.dll!__RtlUserThreadStart()	Unknown
 	ntdll.dll!__RtlUserThreadStart@8�()	Unknown

Wesnoth appears to be thinking that the server hasn't sent any data.

[soliton-]

A bit more detail on the wesnoth.org setup:
With the +dev version clients go on the “trunk“ server, which is the one running on port 15000.
Dev version releases go to the dev server currently on port 14997, so they get redirected there.

Currently you can connect directly to port 14997 fine, as well as older clients get properly redirected to their respective wesnothd version on a different port.

So the issue must be in the client side code and was probably introduced somewhere since 1.13.10.

[soliton-]

50c9b52 this should be the offending commit.
With that the handshake is not done again after redirection, we're only waiting for data.