Fixed in Geany 1.37.1 I think.
https://sourceforge.net/p/scintilla/bugs/2127/ was resolved in https://sourceforge.net/p/scintilla/bugs/2175/ by commit https://sourceforge.net/p/scintilla/code/ci/a9f4676a45e824c4390db6105a72d3c7... and released in Scintilla 3.21.0.
``` $ cat geany-1.37.1/scintilla/version.txt 3211 ```