[Maria-developers] Please review MDEV-11134 Assertion `fixed' failed in Item::const_charset_converter(THD*, CHARSET_INFO*, bool, const char*)

Hello Sergei, can you please review a fix for MDEV-11134. I made it the easiest way, just fixed the assert to cover this special case when Item_param::safe_charset_converter() is called from mysql_prepare_create_table(). But perhaps it can be done in different ways: 1. Do call fix_fields() - Fix mysql_prepare_create_table() to call fix_fields. - Fix Item_param::cleanup() not to set fixed to false. or 2. Sync Item_param::fixed with Item_param::basic_const_item() - Fix Item_param::set_xxx() to set both state=XXX_VALUE and fixed=true. - Fix Item_param::cleanup() not to set fixed to false (like in #1) Thanks!