Core/Spell: check aura positivity per effect on spell hit

- Fixes applying DR to positive effects, and changing duration of whole aura

Closes #19447

(cherry picked from commit 232e631390a504b51d82a7b678b7cf26d49d182a)

2 files changed, 4 insertions, 5 deletions

diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 93ea45dc476..bb739265c0d 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -9208,11 +9208,11 @@ void Unit::IncrDiminishing(SpellInfo const* auraSpellInfo)
         ++diminish.hitCount;
 }
 
-float Unit::ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& duration, Unit* caster, DiminishingLevels previousLevel)
+bool Unit::ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& duration, Unit* caster, DiminishingLevels previousLevel) const
 {
     DiminishingGroup const group = auraSpellInfo->GetDiminishingReturnsGroupForSpell();
     if (duration == -1 || group == DIMINISHING_NONE)
-        return 1.0f;
+        return true;
 
     int32 const limitDuration = auraSpellInfo->GetDiminishingReturnsLimitDuration();
 
@@ -9232,7 +9232,6 @@ float Unit::ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& du
     }
 
     float mod = 1.0f;
-
     switch (group)
     {
         case DIMINISHING_TAUNT:
@@ -9289,7 +9288,7 @@ float Unit::ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& du
     }
 
     duration = int32(duration * mod);
-    return mod;
+    return (duration != 0);
 }
 
 void Unit::ApplyDiminishingAura(DiminishingGroup group, bool apply)
diff --git a/src/server/game/Entities/Unit/Unit.h b/src/server/game/Entities/Unit/Unit.h
index 70271f3023b..d0a246d6b90 100644
--- a/src/server/game/Entities/Unit/Unit.h
+++ b/src/server/game/Entities/Unit/Unit.h
@@ -948,7 +948,7 @@ class TC_GAME_API Unit : public WorldObject
 
         DiminishingLevels GetDiminishing(DiminishingGroup group);
         void IncrDiminishing(SpellInfo const* auraSpellInfo);
-        float ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& duration, Unit* caster, DiminishingLevels previousLevel);
+        bool ApplyDiminishingToDuration(SpellInfo const* auraSpellInfo, int32& duration, Unit* caster, DiminishingLevels previousLevel) const;
         void ApplyDiminishingAura(DiminishingGroup group, bool apply);
         void ClearDiminishings();