Core/Spells: Prevent spell power costs from changing their sign (positive cost cannot become negative)

1 files changed, 5 insertions, 0 deletions

diff --git a/src/server/game/Spells/SpellInfo.cpp b/src/server/game/Spells/SpellInfo.cpp
index 2c62209ce4d..fbe4388e62c 100644
--- a/src/server/game/Spells/SpellInfo.cpp
+++ b/src/server/game/Spells/SpellInfo.cpp
@@ -3775,6 +3775,7 @@ std::vector<SpellPowerCost> SpellInfo::CalcPowerCost(Unit const* caster, SpellSc
 
         // Base powerCost
         int32 powerCost = power->ManaCost;
+        bool initiallyNegative = powerCost < 0;
         // PCT cost from total amount
         if (power->PowerCostPct)
         {
@@ -3906,6 +3907,10 @@ std::vector<SpellPowerCost> SpellInfo::CalcPowerCost(Unit const* caster, SpellSc
             continue;
         }
 
+        // power cost cannot become negative if initially positive
+        if (initiallyNegative != (powerCost < 0))
+            powerCost = 0;
+
         bool found = false;
         for (SpellPowerCost& cost : costs)
         {