Link: https://sourceforge.net/p/scintilla/bugs/2226/
I'm not saying Zsh has it "wrong" per se, just that it seems to be the correct behaviour for POSIX shells, and that in Geany, `*.zsh` files use the regular [Shell filetype](https://github.com/geany/geany/blob/d9f8cdbad58d09f0c18ca8acccb49209263018f0...).