Segmentation fault parsing let %

[the-mikedavis]

Hello! 👋

It looks like there's an edge case that causes the parser to segfault:

$ echo "let %" > test.ncl
$ tree-sitter parse test.ncl
Segmentation fault (core dumped)

I'm not sure where it's coming from - mostly I've seen segfaults come from bugs in external scanners but I've also seen one come from the parser without an external scanner (victorhqc/tree-sitter-prisma#39).

Originally reported in helix-editor/helix#2979

[ErinvanderVeen]

Thank you for reporting this! I'll take a look as soon as I can find the time.

[yannham]

I haven't fiddled with tree-sitter myself, but don't we just feed it with a grammar description in JSON ? That's quite sad if an incorrect definition leads to a segfault 😕

[yannham]

Ah, your PR seems to answer the question: no, it seems there is a hand-written C scanner which was the culprit.