Merge pull request #15452 from Treeston/3.3.5

Core/Unit: Allow mounting for certain transformations
(cherry picked from commit 6cdfe9dc095bd19ea495c22cb41cd82f1212b6cd)

src/server/game/Entities/Unit/Unit.cpp

@@ -11251,6 +11251,10 @@ bool Unit::IsInFeralForm() const
 
 bool Unit::IsInDisallowedMountForm() const
 {
+    if (SpellInfo const* transformSpellInfo = sSpellMgr->GetSpellInfo(getTransForm()))
+        if (transformSpellInfo->HasAttribute(SPELL_ATTR0_CASTABLE_WHILE_MOUNTED))
+            return false;
+
     if (ShapeshiftForm form = GetShapeshiftForm())
     {
         SpellShapeshiftFormEntry const* shapeshift = sSpellShapeshiftFormStore.LookupEntry(form);