Fix help on Windows (#224)

* Fix Windows error caused by invalid path chars
* Prevent warning when displaying HTML help
* Make code more readable
* Ignore generated DLL files
* Document changes

.gitignore

@@ -9,5 +9,6 @@
 /pkgdown/favicon/
 /src/*.o
 /src/*.so
+/src/*.dll
 /vignettes/*.html
 /vignettes/*.R

NEWS.md

@@ -1,5 +1,6 @@
 # box (development version)
 
+* Fix: make interactive HTML module help work on Windows (#223)
 * Fix: prevent segfault in R ≤ 3.6.1 caused by missing declaration of internal R
     symbol (#213)
 * Fix: Allow exporting modules that were previously imported using a different

R/display-help.r

@@ -15,7 +15,7 @@ compile_help.text_help_format = function (x, rd) {
 }
 
 compile_help.html_help_format = function (x, rd) {
-    tools::Rd2HTML(rd, out = tempfile('Rtxt'), package = mock_package_name)
+    tools::Rd2HTML(rd, out = tempfile('Rtxt'), package = c(mock_package_name, NA_character_))
 }
 
 patch_topic_name.text_help_format = function (x, file, topic) {
@@ -28,21 +28,24 @@ patch_topic_name.text_help_format = function (x, file, topic) {
 }
 
 patch_topic_name.html_help_format = function (x, file, topic) {
-    topic = gsub('"', '"',
-                 gsub('<', '&gt;',
-                      gsub('<', '&lt;',
-                           gsub('&', '&amp;', topic))))
+    from = c('&', '<', '>', '"')
+    to = c('&amp;', '&lt;', '&gt;', '&quot;')
+    replace = data.frame(rbind(from, to))
+    topic = Reduce(function (x, r) gsub(r[1L], r[2L], x), replace, topic)
     doc_text = readLines(file)
     doc_text = gsub(mock_package_name, topic, doc_text)
     writeLines(doc_text, file)
 }
 
 display_help_file.text_help_format = function (x, file, topic) {
-    file.show(file, title = gettextf('R Help on %s', dQuote(topic)),
-              delete.file = TRUE)
+    file.show(
+        file, title = gettextf('R Help on %s', dQuote(topic)),
+        delete.file = TRUE
+    )
 }
 
 display_help_file.html_help_format = function (x, file, topic) {
+    topic = sanitize_path(topic)
     port = tools::startDynamicHelp(NA)
     html_path = file.path(tempdir(), sprintf('.R/doc/html/%s.html', topic))
     dir.create(dirname(html_path), recursive = TRUE, showWarnings = FALSE)

R/help.r

@@ -83,7 +83,7 @@ help = function (topic, help_type = getOption('help_type', 'text')) {
         }
     }
 
-    display_help(doc, paste0('module:', mod_name), help_type)
+    display_help(doc, mod_name, help_type)
 }
 
 #' Parse a module’s documentation

R/paths.r

@@ -67,3 +67,11 @@ split_path = function (path) {
 merge_path = function (components) {
     do.call('file.path', as.list(components))
 }
+
+#' \code{sanitize_path(path)} replaces invalid characters in the given
+#' \emph{relative} path, making the result a valid Windows path.
+#' @rdname paths
+sanitize_path = function (path) {
+    win32_reserved_path_chars = '[<>:"/\\|?*]'
+    gsub(win32_reserved_path_chars, '_', path)
+}