Restore retail compatibility after crash fix in OpenContain::killAllContained

[Caball009]

#921 introduced a change that causes this replay replay_02162.zip to mismatch at 11:25.

The issue appears to be that the container size in OpenContain::killAllContained is reset before the loop starts, but functions inside the loop check the container size and behave differently if it's zero.

Here are a couple of examples of checks for infantry garrisoned inside buildings in GarrisonContain::onRemoving and 'downstream' functions:

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/GameLogic/Object/Contain/GarrisonContain.cpp

Line 1673 in 7af8c63

if( getContainCount() == 0 )

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/GameLogic/Object/Contain/GarrisonContain.cpp

Line 1218 in 7af8c63

if( getContainCount() > 0 )

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/GameLogic/Object/Contain/GarrisonContain.cpp

Line 1249 in 7af8c63

if ( getContainCount() > 0 )

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/GameLogic/Object/Contain/GarrisonContain.cpp

Line 1281 in 7af8c63

if( getContainCount() > 0 )

[Caball009]

I'm not sure yet how to reproduce this issue, but it appears the issue arises after player A shoots a Neutron Shell on a civilian building garrisoned by player B with two GLA RPG Troopers with the Demolition upgrade.

[Caball009]

opencontain_mismatch_repros.zip

Here's a custom map + replay created with VS22 debug build for reproduction.

[Caball009]

The key detail is that the contain list should not be swapped (which is tempting for safety reasons) because that changes logic behavior. If m_containList / m_containListSize is empty, it'll make garrisoned civilian buildings unoccupied on the first iteration instead of the last iteration, and the GLA Demolition upgrade would cause damage to the building for each occupant instead of just the last one when hit with a neutron shell.