- Can't reproduce OP with Geany 2.1 currentish git. It is probably an issue with the pascal lexer processing basic code that it doesn't understand (but shouldn't crash). Probably fixed by lexilla upgrade.
- Closed issue #2841 refers to #2813 which is "closed fixed" and was in Geany 2.0 but not relevant since its VTE not Scintilla.
- The tagmanager "random crash" has nothing to do with the VTE crash in #2813 nor likely the OP. Its likely in ctags, did you use pascal on that basic file?
- #3144 notes its ctags upstream issue and reported there, but thats js not basic so not relevant.
It good you are looking at other reported issues but in this case the similarities do not indicate any connection between the causes.