*Fix: Don't apply an aura when it's duration is 0. (for example because of diminishing returns)

This should fix interrupts when casting fear, stun, etc, while the duration is 0.
Fix based on havenard's patch.
Fixes issue 1621
Fixes issue 2271

--HG--
branch : trunk

1 files changed, 6 insertions, 0 deletions

diff --git a/src/game/Spell.cpp b/src/game/Spell.cpp
index 5b60e58b49f..d12998b7b63 100644
--- a/src/game/Spell.cpp
+++ b/src/game/Spell.cpp
@@ -1390,6 +1390,12 @@ SpellMissInfo Spell::DoSpellHitOnUnit(Unit *unit, const uint32 effectMask, bool
                 if (IsChanneledSpell(m_spellInfo))
                     m_originalCaster->ModSpellCastTime(aurSpellInfo, duration, this);
 
+                if (duration <= 0)
+                {
+                    m_spellAura->Remove();
+                    return SPELL_MISS_IMMUNE;
+                }
+
                 if (duration != m_spellAura->GetMaxDuration())
                 {
                     m_spellAura->SetMaxDuration(duration);