Check for invalid file URI

[llrs]

trafficstars

Hi, I submitted a package and got a message/note that was not caught by rhub:

Found the following (possibly) invalid file URI: URI: CODE_OF_CONDUCT.md From: README.md

Perhaps this check could be added when running rhub::check_for_cran()?

[gaborcsardi]

Yeah, need to set _R_CHECK_CRAN_INCOMING_CHECK_FILE_URIS_ to TRUE it seems, https://github.com/wch/r-source/blob/9d1f32c02783585c62ee403f5197b16809a74366/src/library/tools/R/QC.R#L7540

Unfortunately what cran does is AFAICT undocumented, e.g. this is not documented here: https://cran.r-project.org/doc/manuals/r-devel/R-ints.html#Tools

Do you want to submit a PR?

[llrs]

I'll darft a PR. However I think it would be better if this is make more transparent on the R/CRAN level (not sure where to raise the issue).