Also tweak_links() of the form \link[=topic]{text} (#980)

Fixes #979

NEWS.md

@@ -1,5 +1,8 @@
 # roxygen2 (development version)
 
+* Links of the form `\link[=topic]{text}` are now automatically converted to
+  `\link[pkg:topic]{text}` when inherited from other packages (#979)
+
 * Autogenerated function usage for S3/S4 methods is no longer double-escaped 
   (#976).
 

R/utils-rd.R

@@ -78,8 +78,19 @@ tweak_links <- function(x, package) {
 
   if (is.list(x)) {
     if (!is.null(tag) && tag == "\\link") {
-      if (is.null(attr(x, "Rd_option")) && has_topic(x[[1]], package)) {
-        attr(x, "Rd_option") <- structure(package, Rd_tag = "TEXT")
+      opt <- attr(x, "Rd_option")
+      if (is.null(opt)) {
+        if (has_topic(x[[1]], package)) {
+          attr(x, "Rd_option") <- structure(package, Rd_tag = "TEXT")
+        }
+      } else {
+        if (is.character(opt) && length(opt) == 1 && substr(opt, 1, 1) == "=") {
+          topic <- substr(opt, 2, nchar(opt))
+
+          if (has_topic(topic, package)) {
+            attr(x, "Rd_option") <- structure(paste0(package, ":", topic), Rd_tag = "TEXT")
+          }
+        }
       }
     } else if (length(x) > 0) {
       x[] <- map(x, tweak_links, package = package)

tests/testthat/test-utils-rd.R

@@ -12,7 +12,9 @@ test_that("has_topic() works as you'd expect", {
 test_that("can tweak links to point to new package", {
   rd1 <- tweak_links(parse_rd("\\link{abbreviate}"), package = "base")
   rd2 <- tweak_links(parse_rd("\\link[base]{abbreviate}"), package = "base")
+  rd3 <- tweak_links(parse_rd("\\link[=abbreviate]{abbr}"), package = "base")
 
   expect_equal(rd2text(rd1), "\\link[base]{abbreviate}\n")
   expect_equal(rd2text(rd2), "\\link[base]{abbreviate}\n")
+  expect_equal(rd2text(rd3), "\\link[base:abbreviate]{abbr}\n")
 })