Fix gamedata based entity factory (#37)

Due to the nature of member function ptrs on linux, the extension would auto offset the class object ptr allocated by the game. Leading to misaligned memory.

On the topic of misaligned memory, we weren't really guarding against it. So just in the event the engine changes how memory is allocated, or that plugin provides an object size that doesn't allow for 4 bytes aligned memory, we fix that before allocating anything.

extension/pluginentityfactory.cpp

@@ -894,6 +894,8 @@ IServerNetworkable* CPluginEntityFactory::RecursiveCreate(const char* classname,
 
 	size_t entitySize = pCreatingFactory->GetEntitySize();
 
+	static MCall<void> ctorCall;
+
 	IEntityFactory *pBaseFactory = GetBaseFactory();
 	if (pBaseFactory)
 	{
@@ -929,7 +931,7 @@ IServerNetworkable* CPluginEntityFactory::RecursiveCreate(const char* classname,
 	{
 		bIsInstantiating = true;
 
-		CBaseEntityHack* pEnt = (CBaseEntityHack*)engine->PvAllocEntPrivateData(entitySize);
+		CBaseEntityHack* pEnt = (CBaseEntityHack*)engine->PvAllocEntPrivateData(entitySize + ((4 - (entitySize % 4)) % 4));
 		CBaseEntityHack::CBaseEntity_Ctor(pEnt, m_Derive.m_bBaseEntityServerOnly);
 		pEnt->PostConstructor(classname);
 		pNet = pEnt->NetworkProp();
@@ -938,8 +940,9 @@ IServerNetworkable* CPluginEntityFactory::RecursiveCreate(const char* classname,
 	{
 		bIsInstantiating = true;
 
-		CBaseEntityHack* pEnt = (CBaseEntityHack*)engine->PvAllocEntPrivateData(entitySize);
-		(pEnt->*(m_Derive.m_pConstructorFunc))();
+		CBaseEntityHack* pEnt = (CBaseEntityHack*)engine->PvAllocEntPrivateData(entitySize + ((4 - (entitySize % 4)) % 4));
+		ctorCall.Init((void*)m_Derive.m_pConstructorFunc);
+		ctorCall(pEnt);
 		pEnt->PostConstructor(classname);
 		pNet = pEnt->NetworkProp();
 	}

extension/pluginentityfactory.h

@@ -172,8 +172,6 @@ class CPluginEntityFactory : public IEntityFactory, public IEntityDataMapContain
 		DERIVETYPE_MAX
 	};
 
-	typedef void* (CBaseEntity::*RawEntityConstructor)(void);
-
 	struct PluginEntityFactoryDeriveInfo_t
 	{
 		PluginEntityFactoryDeriveType_t m_DeriveFrom;
@@ -182,7 +180,7 @@ class CPluginEntityFactory : public IEntityFactory, public IEntityDataMapContain
 		{
 			PluginEntityFactoryBaseClass_t m_BaseType;
 			Handle_t m_BaseFactoryHandle;
-			RawEntityConstructor m_pConstructorFunc;
+			uintptr_t m_pConstructorFunc;
 		};
 
 		std::string m_iBaseClassname;

product.version

@@ -1 +1 @@
-1.8.3
+1.8.4