(GAS) Block tags are ignored in version 5.5.2 if two abilities share the same parent tags structure.

Block tags are not working correctly in version 5.5.2, it was working in 5.5.1. This is caused by a change done in version 5.5.2. The exact CL is: CL 35930696

With repro project:

1- Play in the ThirdPersonMap
2- Click E to execute GA_Attack
3- Click F to execute GA_Deffend
4- You will see that the ability GA_Defend has not been blocked even including the necessary Block tags.

Without a Repro Project:

1- Create a ThirdPerson template project
2- Create the following Gameplay Tags: Ability.Type.Combat.Defend and Ability.Type.Combat.Attack.
3- Create two Gameplay Abilities: GA_Attack and GA_Defend. 4- For GA_Attack add Ability.Type.Combat.Attack tag, and for GA_Defend add Ability.Type.Combat.Defend tag. Also, add the Ability.Type.Combat tag as a block tag.
5- Open the ThirdPersonCharacter and create an Ability System Component.
6- On BeginPlay, Give the player the two abilities.
7- Add two input entries and execute each GameplayAbility in a different input key.
8- Run the application and try to execute both. You will see that the second ability will not be blocked, even though it has the block tag set correctly.

This is a regression, as not happening in 5.5.1.

UGameplayAbility::DoesAbilitySatisfyTagRequirements(const UAbilitySystemComponent &, const FGameplayTagContainer *, const FGameplayTagContainer *, FGameplayTagContainer *) GameplayAbility.cpp:319
UGameplayAbility::CanActivateAbility(FGameplayAbilitySpecHandle, const FGameplayAbilityActorInfo *, const FGameplayTagContainer *, const FGameplayTagContainer *, FGameplayTagContainer *) GameplayAbility.cpp:483
UAbilitySystemComponent::InternalTryActivateAbility(FGameplayAbilitySpecHandle, FPredictionKey, UGameplayAbility **, TDelegate<…> *, const FGameplayEventData *) AbilitySystemComponent_Abilities.cpp:1788
UAbilitySystemComponent::TryActivateAbility(FGameplayAbilitySpecHandle, bool) AbilitySystemComponent_Abilities.cpp:1653
UFunction::Invoke(UObject *, FFrame &, void *const) Class.cpp:7192
UObject::CallFunction(FFrame &, void *const, UFunction *) ScriptCore.cpp:1147
[Inlined] FFrame::Step(UObject *, void *const) ScriptCore.cpp:482
UObject::ProcessContextOpcode(FFrame &, void *const, bool) ScriptCore.cpp:3114
[Inlined] FFrame::Step(UObject *, void *const) ScriptCore.cpp:482
UObject::execLetBool(UObject *, FFrame &, void *const) ScriptCore.cpp:3008
[Inlined] FFrame::Step(UObject *, void *const) ScriptCore.cpp:482
[Blueprint] BP_ThirdPersonCharacter: Event BeginPlay Event Graph
ProcessLocalScriptFunction(UObject *, FFrame &, void *const) ScriptCore.cpp:1241
ProcessScriptFunction<…>(UObject *, UFunction *, FFrame &, void *const, void [Image Removed](UObject *, FFrame &, void *)) ScriptCore.cpp:1040
`ProcessLocalFunction'::`2'::<lambda_1>::operator()() ScriptCore.cpp:1286
ProcessLocalFunction(UObject *, UFunction *, FFrame &, void *const) ScriptCore.cpp:1302
[Inlined] FFrame::Step(UObject *, void *const) ScriptCore.cpp:482
[Blueprint] BP_ThirdPersonCharacter: F Function /Game/ThirdPerson/Blueprints/BP_ThirdPersonCharacter.BP_ThirdPersonCharacter_C:InpActEvt_F_K2Node_InputKeyEvent_0
ProcessLocalScriptFunction(UObject *, FFrame &, void *const) ScriptCore.cpp:1241
UObject::ProcessInternal(UObject *, FFrame &, void *const) ScriptCore.cpp:1329
UFunction::Invoke(UObject *, FFrame &, void *const) Class.cpp:7192
UObject::ProcessEvent(UFunction *, void *) ScriptCore.cpp:2173
AActor::ProcessEvent(UFunction *, void *) Actor.cpp:1160
TScriptDelegate::ProcessDelegate<…>(void *) ScriptDelegates.h:448
[Inlined] FInputActionHandlerDynamicSignature::Execute(FKey) InputComponent.h:127
FInputActionUnifiedDelegate::Execute(FKey) InputComponent.h:302
UPlayerInput::EvaluateInputDelegates(const TArray<…> &, const float, const bool, const TArray<…> &) PlayerInput.cpp:1553
UEnhancedPlayerInput::EvaluateInputDelegates(const TArray<…> &, const float, const bool, const TArray<…> &) EnhancedPlayerInput.cpp:776
UPlayerInput::ProcessInputStack(const TArray<…> &, const float, const bool) PlayerInput.cpp:1172
APlayerController::ProcessPlayerInput(const float, const bool) PlayerController.cpp:2776
APlayerController::TickPlayerInput(const float, const bool) PlayerController.cpp:5123
APlayerController::PlayerTick(float) PlayerController.cpp:2378
APlayerController::TickActor(float, ELevelTick, FActorTickFunction &) PlayerController.cpp:5276
FActorTickFunction::ExecuteTick(float, ELevelTick, Type, const TRefCountPtr<…> &) Actor.cpp:284
[Inlined] FTickFunctionTask::DoTask(Type, const TRefCountPtr<…> &) TickTaskManager.cpp:306
TGraphTask::ExecuteTask() TaskGraphInterfaces.h:634
UE::Tasks::Private::FTaskBase::TryExecuteTask() TaskPrivate.h:504
[Inlined] FBaseGraphTask::Execute(TArray<…> &, Type, bool) TaskGraphInterfaces.h:482
FNamedTaskThread::ProcessTasksNamedThread(int, bool) TaskGraph.cpp:779
FNamedTaskThread::ProcessTasksUntilQuit(int) TaskGraph.cpp:667
[Inlined] FTaskGraphCompatibilityImplementation::ProcessThreadUntilRequestReturn(Type) TaskGraph.cpp:1453
FTaskGraphCompatibilityImplementation::WaitUntilTasksComplete(const TArray<…> &, Type) TaskGraph.cpp:1526
FTickTaskSequencer::ReleaseTickGroup(ETickingGroup, bool) TickTaskManager.cpp:814
FTickTaskManager::RunTickGroup(ETickingGroup, bool) TickTaskManager.cpp:1865
UWorld::RunTickGroup(ETickingGroup, bool) LevelTick.cpp:773
UWorld::Tick(ELevelTick, float) LevelTick.cpp:1496
UEditorEngine::Tick(float, bool) EditorEngine.cpp:2138
UUnrealEdEngine::Tick(float, bool) UnrealEdEngine.cpp:547
FEngineLoop::Tick() LaunchEngineLoop.cpp:5871
[Inlined] EngineTick() Launch.cpp:69
GuardedMain(const wchar_t *) Launch.cpp:190
LaunchWindowsStartup(HINSTANCE__ *, HINSTANCE__ *, char *, int, const wchar_t *) LaunchWindows.cpp:266
WinMain(HINSTANCE__ *, HINSTANCE__ *, char *, int) LaunchWindows.cpp:317