Client crashes on malformed WML from server

Monadic-Cat commented 3 years ago

Game and System Information

What version of the game are you running? 1.14.17
Where did you download it from? (Steam, Mac App Store, our website, built from source, etc.) Flatpak
What OS are you running? Ubuntu 20.10

Describe the bug

If a server sends the Wesnoth client the message [error] with no closing tag, the game closes with no explanation. If the game was run from a shell, this is printed:

terminate called after throwing an instance of 'config::error'
  what():  Missing closing tag for tag [error]
expected at <unknown>:1
opened at <unknown>:1

To Reproduce

Steps to reproduce the behavior:

Have the game connect to a server.
Have the server send [error] with no closing tag.
The game closes silently.

Expected behavior

I would expect the Wesnoth client to display an error message and probably return to the main menu.

Additional Context

I encountered this bug working on an alternative server implementation, when I had it send [error]message="ur banned d00d"[/error] (note the lack of newlines) to try and get the game to print that error message upon trying to connect to my server.

Pentarctagon commented 3 years ago

What's the alternate implementation, out of curiosity?

Monadic-Cat commented 3 years ago

I only just started it, here: https://github.com/Monadic-Cat/wesmaild (not much to see yet). My goal with it is to play Wesnoth games over email.

Pentarctagon commented 3 years ago

Ah, neat. The WML parsing/serializing in rust will be interesting to see, especially since Wesnoth has two implementations of its own (config and simple_wml).

wesnoth / wesnoth