Campaign reveal code throws Lua error

[GunChleoc]

Lua throws an error when trying to reveal the 2nd campaign (during Barbarian Misson 2). Screenshot attached.

Originally reported on the forum: https://wl.widelands.org/forum/topic/1705/

[wl-zocker (wl-zocker)]

I noticed that in http://bazaar.launchpad.net/~widelands-dev/widelands/trunk/view/head:/src/scripting/lua_game.cc#L629, the error message is shown twice. I do not know whether that if by design. How far does the "if" part go?

[Hans Joachim Desserud (hjd)]

>How far does the "if" part go?

Without brackets, the if only covers the first following line. In other words:

if (some conditional)
  this is only called if conditional is true
  this is called regardless

Which means, you might not get the behaviour you aimed for. Apple had a pretty severe security issue for this reason a while back [1].

This is why it is a good idea to place brackets, even if it is just a single line, to make the code more explicit and avoid issues like this.

In this case it looks like the line printing the error message has been duplicated for some reason, probably accidentally.

[1] https://www.imperialviolet.org/2014/02/22/applebug.html

[SirVer (sirver)]

Fixed in r7444. Weird that this slipped through code review.

[GunChleoc (gunchleoc)]

Not so weird IMO - it might not have been obvious in a diff, and it is hard to test for.

[GunChleoc (gunchleoc)]

Fixed in build19-rc1.