Segmentation fault in game_preload_packet.cc

[Tino]

Hi,

current trunk does segfault:

Program received signal SIGSEGV, Segmentation fault.
At c:\data\bzr\widelands\working\src\game_io\game_preload_packet.cc:117

It does happen in tutorial 2-4 and in a single player game at some point.
For me the easiest way to trigger:
Start tutorial 4 - economy. After the second message the view moves and then the game crashes.

[Hans Joachim Desserud (hjd)]

Thanks for reporting this issue.

I'm able to reproduce this simply by starting and clicking through the dialogs in the Economy tutorial. (r7249 on Ubuntu 14.04)

[SirVer (sirver)]

Fixed in r7251. A one character fix that was very hard to track down :).

[Hans Joachim Desserud (hjd)]

Ok, wow. :)

Could we prefer non-abbreviated variable names in the future? It's usually makes the names more descriptive/readable (also benefits new contributors), and would make it harder to introduce such bugs in the future. Don't think we can make a code check rule for this (easily), but should be possible to catch it during code review.

[SirVer (sirver)]

I agree that no abberviated names are preferable. however, brn (bottom right neighbor), bln, tln, trn, rn, ln are idioms in Widelands - they are used in many places. I opted for local style instead of non-abbreviation.

Also, this was just a copy & pasto. It is kinda obvious that you would check the variable you just calculated and not one that you've used a few lines further up already. Especially since the pattern is repeated multiple times.

No, I think this mistake was hard to avoid. And I am happy if it stays the only bug in the new rendering code - that was a very difficult rewrite.

[GunChleoc (gunchleoc)]

All bow before the sharp eyes!

[SirVer (sirver)]

Well, I wrote that code and seing an index of -1 trying to be accessed while I remembered explicitly checking for this index made it rather obvious that I had this error some place.

[GunChleoc (gunchleoc)]

Fixed in build19-rc1.