Core/Battleground:

Add missing NULL pointer check for player if is not in world

Core/Spell:
Add absolute value for delta because can be nevgative

Close #10846

src/server/game/Spells/SpellInfo.cpp

@@ -452,7 +452,7 @@ int32 SpellEffectInfo::CalcValue(Unit const* caster, int32 const* bp, Unit const
                 float preciseBasePoints = ScalingMultiplier * multiplier;
                 if (DeltaScalingMultiplier)
                 {
-                    float delta = DeltaScalingMultiplier * ScalingMultiplier * multiplier * 0.5f;
+                    float delta = fabs(DeltaScalingMultiplier * ScalingMultiplier * multiplier * 0.5f);
                     preciseBasePoints += frand(-delta, delta);
                 }