neovim: Indentation is incompatible with tree-sitter highlighting

[t-gebauer]

Indentation breaks in subtle ways, when using nvim-treesitter for syntax highlighting. For example, the following code is indented

(print "foo(bar"
            true)

instead of

(print "foo(bar"
       true)

The reason seems to be, that some parts of the indentation function check for syntax highlighting with synID. But synID returns 0 everywhere, because no "normal" syntax highlighting takes place, instead highlighting is based on treesitter queries.

Output of :lua= vim.inspect_pos():

{                                                                                                                                  
  buffer = 1,
  col = 12,
  extmarks = {},
  row = 7,
  semantic_tokens = {},
  syntax = {},
  treesitter = { {
      capture = "string",
      hl_group = "@string.fennel",
      hl_group_link = "String",
      lang = "fennel",
      metadata = {}
    } }
}