Core/Spells: Define and implement CAST_FLAG_NO_GCD

src/server/game/Spells/Spell.cpp

@@ -3231,7 +3231,7 @@ void Spell::handle_immediate()
             // Apply duration mod
             if (Player* modOwner = m_caster->GetSpellModOwner())
                 modOwner->ApplySpellMod(m_spellInfo->Id, SPELLMOD_DURATION, duration);
-            
+
             // Apply haste mods
             m_caster->ModSpellCastTime(m_spellInfo, duration, this);
 
@@ -3762,7 +3762,7 @@ void Spell::SendSpellStart()
         castFlags |= CAST_FLAG_POWER_LEFT_SELF;
 
     if (m_spellInfo->RuneCostID && m_spellInfo->PowerType == POWER_RUNE)
-        castFlags |= CAST_FLAG_UNKNOWN_19;
+        castFlags |= CAST_FLAG_NO_GCD; // not needed, but Blizzard sends it
 
     WorldPacket data(SMSG_SPELL_START, (8+8+4+4+2));
     if (m_CastItem)
@@ -3820,19 +3820,19 @@ void Spell::SendSpellGo()
         && m_spellInfo->RuneCostID
         && m_spellInfo->PowerType == POWER_RUNE)
     {
-        castFlags |= CAST_FLAG_UNKNOWN_19;                   // same as in SMSG_SPELL_START
+        castFlags |= CAST_FLAG_NO_GCD;                       // not needed, but Blizzard sends it
         castFlags |= CAST_FLAG_RUNE_LIST;                    // rune cooldowns list
     }
 
     if (m_spellInfo->HasEffect(SPELL_EFFECT_ACTIVATE_RUNE))
-    {
         castFlags |= CAST_FLAG_RUNE_LIST;                    // rune cooldowns list
-        castFlags |= CAST_FLAG_UNKNOWN_19;                   // same as in SMSG_SPELL_START
-    }
 
     if (m_targets.HasTraj())
         castFlags |= CAST_FLAG_ADJUST_MISSILE;
 
+    if (!m_spellInfo->StartRecoveryTime)
+        castFlags |= CAST_FLAG_NO_GCD;
+
     WorldPacket data(SMSG_SPELL_GO, 50);                    // guess size
 
     if (m_CastItem)

src/server/game/Spells/Spell.h

@@ -57,7 +57,7 @@ enum SpellCastFlags
     CAST_FLAG_UNKNOWN_16         = 0x00008000,
     CAST_FLAG_UNKNOWN_17         = 0x00010000,
     CAST_FLAG_ADJUST_MISSILE     = 0x00020000,
-    CAST_FLAG_UNKNOWN_19         = 0x00040000,
+    CAST_FLAG_NO_GCD             = 0x00040000,              // no GCD for spell casts from charm/summon (vehicle spells is an example)
     CAST_FLAG_VISUAL_CHAIN       = 0x00080000,
     CAST_FLAG_UNKNOWN_21         = 0x00100000,
     CAST_FLAG_RUNE_LIST          = 0x00200000,