off-by-one symbol range for headings ending with emoji

[drowning-cat]

I'm not very skilled with this kind of things, so I apologize in advance.

It looks like there might be an off-by-one error when returning textDocument/documentSymbol selectionRange for a heading that ends with an emoji. This was originally reported here: folke/snacks.nvim#2704.

For a markdown file like:

## 45
## 🚀

I would expect the second heading to have the following selection range:

"selectionRange": {
  "start": { "line": 1, "character": 0 },
  "end":   { "line": 1, "character": 5 }
},

However, the actual result appears to be "character": 6 for the end position.

Could you please confirm whether this is a valid issue?

[artempyanykh]

Thanks for reporting this @drowning-cat! I think you're correct. #455 should fix the issue.

[drowning-cat]

Thank you :)