Merge commit 'c5615f812ccc9d235747a1c5ba396ac2e9a23690' into daimini/gitflow_211206_o3de

Signed-off-by: Danilo Aimini <82231674+AMZN-daimini@users.noreply.github.com>

# Conflicts:
#	Code/Framework/AzToolsFramework/Tests/Prefab/PrefabTestFixture.cpp
#	Code/Framework/AzToolsFramework/Tests/Prefab/PrefabTestFixture.h
#	Code/Framework/AzToolsFramework/Tests/UI/EntityOutlinerTests.cpp

Code/Framework/AzToolsFramework/AzToolsFramework/ToolsComponents/TransformComponent.cpp

@@ -860,18 +860,20 @@ namespace AzToolsFramework
                     return;
                 }
 
-                bool isDuringUndoRedo = false;
-                EBUS_EVENT_RESULT(isDuringUndoRedo, AzToolsFramework::ToolsApplicationRequests::Bus, IsDuringUndoRedo);
-                if (!isDuringUndoRedo)
+                bool suppressTransformChangedEvent = m_suppressTransformChangedEvent;
+                // temporarily disable calling OnTransformChanged, because CheckApplyCachedWorldTransform is not guaranteed
+                // to call it when m_cachedWorldTransform is identity. We send it manually later.
+                m_suppressTransformChangedEvent = false;
+                // When parent comes online, compute local TM from world TM.
+                CheckApplyCachedWorldTransform(parentTransform->GetWorldTM());
+                if (!m_initialized)
                 {
-                    // When parent comes online, compute local TM from world TM.
-                    CheckApplyCachedWorldTransform(parentTransform->GetWorldTM());
-                }
-                else
-                {
-                    // During undo operations, just apply our local TM.
+                    m_initialized = true;
+                    // If this is the first time this entity is being activated, manually compute OnTransformChanged
+                    // this can occur when either the entity first created or undo/redo command is performed
                     OnTransformChanged(AZ::Transform::Identity(), parentTransform->GetWorldTM());
                 }
+                m_suppressTransformChangedEvent = suppressTransformChangedEvent;
 
                 auto& parentChildIds = GetParentTransformComponent()->m_childrenEntityIds;
                 if (parentChildIds.end() == AZStd::find(parentChildIds.begin(), parentChildIds.end(), GetEntityId()))

Code/Framework/AzToolsFramework/AzToolsFramework/ToolsComponents/TransformComponent.h

@@ -242,6 +242,9 @@ namespace AzToolsFramework
             // element is used rather than a data element.
             bool m_addNonUniformScaleButton = false;
 
+            // Used to check whether entity was just created vs manually reactivated. Set true after OnEntityActivated is called the first time.
+            bool m_initialized = false;
+
             // Deprecated
             AZ::InterpolationMode m_interpolatePosition;
             AZ::InterpolationMode m_interpolateRotation;