ProjectSkyfire/SkyFireEMU_rebase — comment on commit 535c110db2996ba495ee094ef602d82d325a0c0f
File: src/server/game/Spells/Auras/SpellAuraEffects.cpp line 4656
By Warpten:

Can be simplified to
GetBase()->SetDuration((GetBase()->GetUnitOwner()->GetPower(POWER_HOLY_POWER) + 1) * 4000, true);