Always resolve to "anchored" Rd xrefs

[jeroen]

In order to improve cross-package links in the new single-page-html documentation, CRAN will start showing NOTEs for Rd pages which link to a topic that exists in multiple CRAN packages, such as toJSON (in jsonlite, RJSONIO, rjson).

Seemingly it is not trivial at CMD check time to resolve a topic to a given based on the package imports/suggests. They suggest you use "anchored" Rd links, which simply means using the full \link[pkg:topic]{topic} syntax.

If possible, way to reduce some of the fallout would be to resolve a [topic] name to the full \link[pkg:topic]{topic} at roxygenize time, by inspecting at the package namespace, i.e. to automatically determine the pkg: value when unset:

roxygen2/R/markdown-link.R

Lines 12 to 23 in 2357de6

	#' MARKDOWN LINK TEXT CODE RD
	#' -------- --------- ---- --
	#' [fun()] fun() T \\link[=fun]{fun()}
	#' [obj] obj F \\link{obj}
	#' [pkg::fun()] pkg::fun() T \\link[pkg:file]{pkg::fun()}
	#' [pkg::obj] pkg::obj F \\link[pkg:file]{pkg::obj}
	#' [text][fun()] text F \\link[=fun]{text}
	#' [text][obj] text F \\link[=obj]{text}
	#' [text][pkg::fun()] text F \\link[pkg:file]{text}
	#' [text][pkg::obj] text F \\link[pkg:file]{text}
	#' [s4-class] s4 F \\linkS4class{s4}
	#' [pkg::s4-class] pkg::s4 F \\link[pkg:file]{pkg::s4}