make sure column is defined

[randy3k]

an attempt to fix #609

[renkun-ken]

LGTM

[randy3k]

Let’s wait and see if @klmr could confirm that it fixes the issue.

[klmr]

Unfortunately this does not fix the issue. And when logging the value of column I can see that it is -1 with the minimal test case from #609.

Of course the code could simply be modified to test for values ≤ 0 but maybe we should figure out why the value is negative in the first place. This seems to come directly from lintr::lint, correct?

Invoking that on the provided example file returns the following result:

structure(list(structure(list(filename = "/path/to/test.r",
    line_number = 2L, column_number = 0L, type = "style", message = "Indentation should be 4 spaces but is 0 spaces.",
    line = "b = 2", ranges = list(c(0L, 4L)), linter = "indentation_linter"), class = c("lint",
"list"))), class = c("lints", "list"))

[randy3k]

In this case, the bug is actually triggered by code_point_to_unit which assumes that the input is always >=0. Hopefully it will fix the issue.

[klmr]

Hallelujah, I think that fixes it. And it even returns the correct (rather than just an arbitrary) position for the diagnostic to the language client, I believe.

[randy3k]

Great, let's merge it.