Summary
A stacking GameplayEffect incorrectly triggers its OverflowEffect on the first application.
What Type of Bug are you experiencing?
Gameplay Effect
Steps to Reproduce
Create an Infinite GE with Stack Per Target and StackLimitCount 3.
Add an OverflowEffect and enable Deny Overflow Application and Clear Stack on Overflow.
Apply the GE once with StackCount 1 to a target with no existing stack.
Expected Result
StackCount should become 1. Overflow should only occur when applying beyond 3 stacks.
Observed Result
The OverflowEffect executes immediately and the stacking GE is rejected.
Affects Versions
5.8
Platform(s)
Windows
Additional Notes
The initial-application branch in FActiveGameplayEffectsContainer::ApplyGameplayEffectSpec() calls HandleActiveGameplayEffectStackOverflow() unconditionally. The handler does not verify whether OldSpec.StackCount + OverflowingSpec.StackCount exceeds the limit.
Reproduced in Standalone with Authority, so replication is not involved.