Fix endless loop comparing Selector_List to List

Author: mgreter

src/ast.cpp

@@ -448,10 +448,10 @@ namespace Sass {
   }
 
   // Selector lists can be compared to comma lists
-  bool Selector_List::operator==(const Expression& rhs) const
+  bool Selector_List::operator== (const Expression& rhs) const
   {
     // solve the double dispatch problem by using RTTI information via dynamic cast
-    if (List_Ptr_Const ls = Cast<List>(&rhs)) { return *this == *ls; }
+    if (List_Ptr_Const ls = Cast<List>(&rhs)) { return *ls == *this; }
     if (Selector_Ptr_Const ls = Cast<Selector>(&rhs)) { return *this == *ls; }
     // compare invalid (maybe we should error?)
     return false;