segfault eeschema at save whole project

eeschema/class_library.cpp

@@ -241,6 +241,9 @@ LIB_COMPONENT* CMP_LIBRARY::AddComponent( LIB_COMPONENT* aComponent )
     {
         LIB_ALIAS* alias = FindAlias( newCmp->m_AliasList[ i ] );
         
+        if( alias == NULL )
+    	    break;
+
         if( alias->GetComponent()->GetName().CmpNoCase( newCmp->GetName() ) != 0 )
         {
             wxString msg1;