Strategic Movement Passing Bug Explained

[mooxe]

Through a collaborative effort we have got to the bottom of a movement bug on the strategic layer of LSA.

The issue is moving a friendly unit to a map with two friendly units already on it while moving one of them out. If your opponent attacks in to your move in this scenario (TEST 1) both BGs pass each other no matter what BG speed is calculated at. Movement and blocking behaves as intended if only one friendly BG existed on the map prior to the strategic moves. The image should illustrate the scenarios better.

Note that the screenshots in this image are from Gold Juno Sword and depict both strategic sides of the same save game file taken from two computers back to back. No reason to believe this bug is not present in stock LSA.

You can work around the passing bug by merging both Axis units. If you merge, the recon unit will block the Allied movement south (TEST 2 results). A work around that does not work is disbanding one of the battlegroups into the map you are attacking into.

The bug has led us to believe there is something potentially wrong in the order of how to game code conducts strategic moves.

[davidss]

Nice work Mooxe! Thanks.
Hopefully with this information a solution to the problem will be worked out.

[Aetius2]

Nice bit of investigating and visualising the problem.

[SchnelleMeyer]

Very clearly explained Mooxe. Thank you. Now this is a bug that can cause really annoying consequences with the strategic moves. Hopefully this game continues to be supported with patches so this can be fixed.

[Tejszd]

Great explanation/find on how the problem occurs!

Fingers crossed Matrix/Steve now can recreate the problem and fix the code with an LSA patch to prevent this from happening....

[SteveMcClaire]

Note that the screenshots in this image are from Gold Juno Sword and depict both strategic sides of the same save game file taken from two computers back to back.

Hi Mooxe - thanks for the bug report. Where can I get the GJS mod you were using to test this?

[mooxe]

Hi Steve, thanks for the response...

http://www.closecombatseries.net/downlo ... taller.zip

Save file attached that I used.

[davidss]

GJS11 download at CCS
http://www.closecombatseries.net/CCS/mo ... t&lid=4247

And ALLIED_318 save file, before moves were done:

[argilas]

Great explanation/find on how the problem occurs!

Thank you, Mooxe, for visualizing this bug

Fingers crossed Matrix/Steve now can recreate the problem and fix the code with an LSA patch to prevent this from happening....

I hope so too. There's incoming LSA mods (Stalingrad, Radzymin44 3.0, Rhineland45 1.0,...) that will be greatly benefitted with a fixing patch.

[Kanov]

Hello,

related to the topic, this was posted by user kweniston in 2012:

https://www.matrixgames.com/forums/view ... 9&t=218401

on behalf of user zcharles. There are three observations, the last two I believe were fixed in the patches but the first one sounds very similar to what mooxe posted:

There are two regions, A and B; some time when a BG moves from A to B and one secondary BG (that who does not lead the battle) from B to A, they do not met and simply exchange regions. This allows surrounded BGs to flee, with a little luck.

[Kanov]

I've got that bug scenario on vanilla LSA GC vs AI in case you want to try there:

Move KG Stagaard from Uden to Gemert
Move KG Graebner from Veghel to Gemert
Move StuG Brigade 280 from Uden to Veghel

The British armored BG in Veghel will move to Uden exchanging places with the StuG brigade.

[Tejszd]

Thanks for posting that Kanov as we don't want the mod being pointed to as the cause.

[davidss]

Thanks Kanov.
... on vanilla LSA GC vs AI

[Tejszd]

SteveMcClaire, have you duplicated the problem in LSA?

[SteveMcClaire]

Yes I have reproduced the bug and I have a fix. The issue happens when the destination map is still full of friendly BGs at the time the faster of the head-to-head BGs tries to move there. In Kanov's example this is StuG Bde 280 (the British armored BG's speed is reduced a lot due to fatigue and low cohesion.)

This will be in the next update to LSA, though I don't have an estimate of when that will be available yet.

[davidss]

Thanks Steve for your continued support for LSA

[Tejszd]

Thank you Steve! Good news....

[SchnelleMeyer]

Thanks for the quick resolution Steve. I am really impressed with how Matrix continues its support for the Close Combat series.

[davidss]

Any idea when the update for this "blocking moves" bug is going to be available?
LSA was released 13 years ago!
It would be nice to play a Grand Campaign with all features working, thanks.

[SteveMcClaire]

I do not have an estimate on when the update will be available, no. It will be a few weeks at the very earliest.