The visual actor unit causes SEGFAULT when running without graphics

[elexis]

The attached replay crashes with a SEGFAULT when doing a serializationtest on it (r18742).

Alpha 20 doesn't show this behavior, so it's a regression.

[elexis]

SEGFAULT on turn 1. Same replay as in attachment:hash_mismatch_on_rejoin_reproduce_bb_r18742.7z:ticket:3637​

[elexis]

Backtrace:

Thread #1 [pyrogenesis] 11290 [core: 2] (Suspended : Signal : SIGSEGV:Segmentation fault)	
	CUnit::ReloadObject() at Unit.cpp:106 0x73a704	
	CUnit::SetEntitySelection() at Unit.cpp:96 0x73b4c8	
	CCmpVisualActor::Deserialize() at CCmpVisualActor.cpp:268 0x55a8d3	
	CComponentManager::DeserializeState() at ComponentManagerSerialization.cpp:374 0x49fd3f	
	CSimulation2Impl::Update() at Simulation2.cpp:403 0x4816f6	
	CSimulation2::Update() at Simulation2.cpp:691 0x482d0f	
	CReplayPlayer::Replay() at Replay.cpp:224 0x5b1ed0	
	RunGameOrAtlas() at main.cpp:474 0x4307b1	
	main() at main.cpp:567 0x4212b7	

Notice it occurs when deserializing the actor seed for visual actors, since the line m_Unit->SetEntitySelection(m_VariantSelections); in CCmpVisualActor is the calling code that breaks, so I assume it is r18266.

[sanderd17]

Does it also happen when doing a serialization test on a visual replay? I guess it's just related to not all graphics code being initialized in regular replay, in which case we should just add a null check to avoid that segfault from popping up.

[elexis]

Serializationtestmode is only implemented for nonvisual replaymode.

(I hope that code doesn't break when doing regular rejoins. We wouldn't have noticed OOS issues since we have OOS on rejoin with rnd() probability since alpha 19. (Hash mismatch on rejoin with same textual sim dump))

[sanderd17]

You'd notice a segfault, and I don't see a reason why it would segfault in non visual replay and oos in visual replay. Those things are rather unrelated (one is a result of the serialization state and the other is a result of the game state).

[elexis]

Index: source/simulation2/components/CCmpVisualActor.cpp
===================================================================
--- source/simulation2/components/CCmpVisualActor.cpp	(revision 18749)
+++ source/simulation2/components/CCmpVisualActor.cpp	(working copy)
@@ -260,14 +260,14 @@ public:
 		u32 oldSeed = GetActorSeed();
 
 		SerializeCommon(deserialize);
 
 		// If we serialized a different seed or different actor, reload actor
-		if (oldSeed != GetActorSeed() || m_BaseActorName != m_ActorName)
+		//if (oldSeed != GetActorSeed() || m_BaseActorName != m_ActorName)
 			ReloadActor();
-		else
-			m_Unit->SetEntitySelection(m_VariantSelections);
+		//else
+		//	m_Unit->SetEntitySelection(m_VariantSelections);
 
 		fixed repeattime = m_AnimSyncRepeatTime; // save because SelectAnimation overwrites it
 
 		if (m_AnimRunThreshold.IsZero())
 			SelectAnimation(m_AnimName, m_AnimOnce, m_AnimSpeed, m_SoundGroup);

Workaround by Itms.

[Itms]

In 18812:

In CCmpVisualActor, m_Unit is not initialized when running without graphics, so we must check that pointer everytime. Also make one call consistent with the rest of the file.

Fixes #4238, refs #3952