Core/Spells: Define and implement SPELL_ATTR4_PROC_ONLY_ON_DUMMY.

Fixes #2685
Fixes #2573

src/server/game/Miscellaneous/SharedDefines.h

@@ -409,7 +409,7 @@ enum SpellAttr3
 enum SpellAttr4
 {
     SPELL_ATTR4_UNK0                             = 0x00000001, //  0
-    SPELL_ATTR4_UNK1                             = 0x00000002, //  1 proc on finishing move?
+    SPELL_ATTR4_PROC_ONLY_ON_DUMMY               = 0x00000002, //  1 proc only on SPELL_EFFECT_DUMMY?
     SPELL_ATTR4_UNK2                             = 0x00000004, //  2
     SPELL_ATTR4_UNK3                             = 0x00000008, //  3
     SPELL_ATTR4_UNK4                             = 0x00000010, //  4 This will no longer cause guards to attack on use??

src/server/game/Spells/Spell.cpp

@@ -1201,7 +1201,6 @@ void Spell::DoAllEffectOnTarget(TargetInfo* target)
     m_spellAura = NULL; // Set aura to null for every target-make sure that pointer is not used for unit without aura applied
 
                             //Spells with this flag cannot trigger if effect is casted on self
-                            // Slice and Dice, relentless strikes, eviscerate
     bool canEffectTrigger = !(m_spellInfo->AttributesEx3 & SPELL_ATTR3_CANT_TRIGGER_PROC) && unitTarget->CanProc() && CanExecuteTriggersOnHit(mask);
     Unit* spellHitTarget = NULL;
 
@@ -1597,12 +1596,12 @@ void Spell::DoTriggersOnSpellHit(Unit* unit, uint8 effMask)
     // this is executed after spell proc spells on target hit
     // spells are triggered for each hit spell target
     // info confirmed with retail sniffs of permafrost and shadow weaving
-    if (!m_hitTriggerSpells.empty() && CanExecuteTriggersOnHit(effMask))
+    if (!m_hitTriggerSpells.empty())
     {
         int _duration = 0;
         for (HitTriggerSpells::const_iterator i = m_hitTriggerSpells.begin(); i != m_hitTriggerSpells.end(); ++i)
         {
-            if (roll_chance_i(i->second))
+            if (CanExecuteTriggersOnHit(effMask, i->first) && roll_chance_i(i->second))
             {
                 m_caster->CastSpell(unit, i->first, true);
                 sLog->outDebug(LOG_FILTER_SPELLS_AURAS, "Spell %d triggered spell %d by SPELL_AURA_ADD_TARGET_TRIGGER aura", m_spellInfo->Id, i->first->Id);
@@ -7092,17 +7091,17 @@ void Spell::CallScriptAfterUnitTargetSelectHandlers(std::list<Unit*>& unitTarget
     }
 }
 
-bool Spell::CanExecuteTriggersOnHit(uint8 effMask) const
+bool Spell::CanExecuteTriggersOnHit(uint8 effMask, SpellInfo const* spellInfo) const
 {
-    // check which effects can trigger proc
-    // don't allow to proc for dummy-only spell target hits
-    // prevents triggering/procing effects twice from spells like Eviscerate
-    for (uint8 i = 0;effMask && i < MAX_SPELL_EFFECTS; ++i)
+    bool only_on_dummy = (spellInfo && (spellInfo->AttributesEx4 & SPELL_ATTR4_PROC_ONLY_ON_DUMMY));
+    // If triggered spell has SPELL_ATTR4_PROC_ONLY_ON_DUMMY then it can only proc on a casted spell with SPELL_EFFECT_DUMMY
+    // If triggered spell doesn't have SPELL_ATTR4_PROC_ONLY_ON_DUMMY then it can NOT proc on SPELL_EFFECT_DUMMY (needs confirmation)
+    for (uint8 i = 0;i < MAX_SPELL_EFFECTS; ++i)
     {
-        if (m_spellInfo->Effects[i].Effect == SPELL_EFFECT_DUMMY)
-            effMask &= ~(1<<i);
+        if ((effMask & (1 << i)) && (only_on_dummy == (m_spellInfo->Effects[i].Effect == SPELL_EFFECT_DUMMY)))
+            return true;
     }
-    return effMask;
+    return false;
 }
 
 void Spell::PrepareTriggersExecutedOnHit()

src/server/game/Spells/Spell.h

@@ -633,7 +633,7 @@ class Spell
         void CallScriptAfterUnitTargetSelectHandlers(std::list<Unit*>& unitTargets, SpellEffIndex effIndex);
         std::list<SpellScript*> m_loadedScripts;
 
-        bool CanExecuteTriggersOnHit(uint8 effMask) const;
+        bool CanExecuteTriggersOnHit(uint8 effMask, SpellInfo const* spellInfo = NULL) const;
         void PrepareTriggersExecutedOnHit();
         typedef std::list< std::pair<SpellInfo const*, int32> > HitTriggerSpells;
         HitTriggerSpells m_hitTriggerSpells;