When performing specific left join using non integer keys, I get an error (Internal error On clause filter...)

first things first: this is the first time I submit a bug, please forgive me if anything is wrong or not clear enough
I'm attaching a file with the full test in order to reproduce the bug. You can see the full picture there. Let me know if I can be of any help. We were trying to debug the cpp files, and got to line 2611 in jlf_tuplejoblist.cpp but nobody around here has any experience with cpp... sorry. BTW, this was performed both on an old Debian package and on a fresh install from the git repository.