Add-ons server inaccessible with MSVC build

[Wedge009]

Game and System Information

Self-compiled 1.15.18+dev (9c2ad49) and 1.17.0+dev (e49b5c7) on Windows 7.

Describe the bug

Attempting to access the add-ons server results in a 'Remote host disconnected' error message. Logs report:

error network: network_asio::error thrown during transaction with add-on server; "The handle is invalid"
error general: Remote host disconnected.

Attempting to access the add-ons server a second time results in a crash...

In contrast, there are no issues with logging in to the MP server. Accessing the add-ons server is fine on 1.14.17 release on Windows 7. No such issues on Linux.

To Reproduce

1. On Windows 7 start Wesnoth 1.15+.
2. Click Add-ons in the main menu.
3. Click Connect.
4. Repeating steps 2 and 3 results in a crash.

Expected behaviour

List of add-ons for the running Wesnoth version is downloaded and then displayed.

Additional context

https://forums.wesnoth.org/viewtopic.php?t=54955 may be related as it has the same symptoms but the exception message is different. Like the reporter there, accessing the web page from Internet Explorer is fine.

[Wedge009]

Running in debug mode doesn't have the crash on second connection attempt so maybe there's a race condition or something happening.

Stack trace:

wesnoth.exe!addons_client::wait_for_transfer_done(const std::string & status_message, addons_client::transfer_mode mode) Line 694	C++
wesnoth.exe!addons_client::connect() Line 81	C++
wesnoth.exe!`anonymous namespace'::addons_manager_ui(const std::string & remote_address) Line 77	C++
wesnoth.exe!manage_addons() Line 248	C++
wesnoth.exe!gui2::dialogs::title_screen::pre_show::__l2::<lambda>() Line 288	C++

Upon attempting to connect to the add-ons server the exception seems to be thrown when showing the little dialogue that would normally show download progress.

wesnoth/src/addon/manager_ui.cpp

Lines 73 to 91 in e49b5c7

	try {
	addons_client client(remote_address);
	client.connect();
	gui2::dialogs::addon_manager dlg(client);
	dlg.show();
	need_wml_cache_refresh = dlg.get_need_wml_cache_refresh();
	} catch(const config::error& e) {
	ERR_CFG << "config::error thrown during transaction with add-on server; \""<< e.message << "\"" << std::endl;
	gui2::show_error_message(_("Network communication error."));
	} catch(const network_asio::error& e) {
	ERR_NET << "network_asio::error thrown during transaction with add-on server; \""<< e.what() << "\"" << std::endl;
	gui2::show_error_message(_("Remote host disconnected."));
	} catch(const filesystem::io_exception& e) {
	ERR_FS << "filesystem::io_exception thrown while installing an addon; \"" << e.what() << "\"" << std::endl;
	gui2::show_error_message(_("A problem occurred when trying to create the files necessary to install this add-on."));
	} catch(const invalid_pbl_exception& e) {
	ERR_CFG << "could not read .pbl file " << e.path << ": " << e.message << std::endl;

wesnoth/src/addon/client.cpp

Line 79 in e49b5c7

wait_for_transfer_done(msg, transfer_mode::connect);

wesnoth/src/addon/client.cpp

Lines 692 to 701 in e49b5c7

	gui2::dialogs::network_transmission stat(*cd, _("Add-ons Manager"), status_message);
	if(!stat.show()) {
	// Notify the caller chain that the user aborted the operation.
	if(mode == transfer_mode::connect) {
	throw user_disconnect();
	} else {
	throw user_exit();
	}
	}

At that point I just get the exception network_asio::error with message 'The handle is invalid'. Not sure what handle that is. (Edit: setting a break-point at all the times network_asio.cpp throws an error didn't come up with anything, but they may be different error objects.)

[Pentarctagon]

Does it happen with the Steam or SourceForge versions, since those are compiled in a different way (assuming you're compiling with VS yourself)?

[Wedge009]

I just retried using 1.15.18 win64 downloaded from SourceForge. Strange, seems to work just fine. I'll try a full recompile, it was working fine previously...

(Yeah, self-compiled in VS2019.)

As an aside, I confirmed #4508 still happens with the official build (it's using SDL 2.0.12) so that one definitely isn't me doing something wrong/different.

[Wedge009]

Hmm, no difference. The relevant differences I'm seeing in the Libraries report is that I'm using boost 1.77 over 1.74, openssl 1.1.1l over 1.1.1i and SDL 2.0.16 over 2.0.12. boost 1.77 has been around since August, I'm pretty sure Add-ons were working before that but maybe it really is just a case of something I'm doing differently.

Closing as 'not an issue' (from project's point of view).

[Pentarctagon]

The official Windows builds don't use VS, they're cross-compiled from Linux, so that's a big difference (even though in a perfect world they'd be entirely similar).

[Wedge009]

Yes, I'm aware of that - or at least that they aren't built from MSVC.

[Pentarctagon]

Something you could try if you're feeling adventurous would be to see if wesnoth can be built with clang instead, and if that works see if the same bug still occurs.

[Wedge009]

Thanks for the suggestion. I decided to leave it for now as I got stuck on boost dependencies - it requires boost generated by clang rather than msvc in which case I wonder if I'm better off trying again with boost 1.74 instead, since network_asio appears to be built atop boost.

[Pentarctagon]

Alright. Are you able to check if this happens on Windows 10 as well? If it's just Windows 7 then I'd be fine with this staying closed, but if it also happens on Windows 10 it'd be good to keep it open given that building with VS is the primary way Windows devs are expected to build Wesnoth.

[Wedge009]

I don't have a build environment on Win10 (only have it in the first place on slow laptops because, well, MS still has a monopoly on pre-built machines) so again I just copied my Win7-built binaries to a Win10 machine. The issue happens there as well, but I as mentioned above, I can't tell if it's an issue specific to the compiler (eg if it was compiled with MSVC on Win10 would it still be a problem?), with boost, or something else entirely.

[Wedge009]

@Vultraz I saw you mention that you're already using VS2022 - can you advise if you have any issues accessing the Add-ons server with your builds? If not, it suggests an issue with my boost set-up or something else specific to my Windows 7 environment.

[Wedge009]

Rebuilt with boost 1.78 and SDL 2.0.18 and can access add-ons server again. Odd.

[Wedge009]

I forgot about this issue.

Out of curiosity I retested this on both VS2019 on Windows 7 and VS2022 on Windows 10. For whatever reason I've since forgotten, I still choose to compile 1.16 branch via regular VS project, but I adopted the cmake+vcpkg builds for master. The network_asio invalid handle error still occurs in the former while the latter works fine. boost 1.80, SDL 2.24.2 (VS project) and SDL 2.0.22 (cmake).

Leaving this closed because it only occurs in my non-standard VS project build.