pkg_file_lua() should have thrown an error if the expected Lua file does not exist, but it didn't because we only checked the existence of the rmarkdown/lua folder, then we used file.path() to construct the paths, which doesn't check for the existence of files

Author: yihui

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: rmarkdown
 Type: Package
 Title: Dynamic Documents for R
-Version: 2.4.2
+Version: 2.4.3
 Authors@R: c(
   person("JJ", "Allaire", role = "aut", email = "jj@rstudio.com"),
   person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),

NEWS.md

@@ -5,6 +5,8 @@ rmarkdown 2.5
 
 - `html_document` gains the `anchor_sections` argument, which is `TRUE` by default, so that readers can get links to section headers easily---when you mouse over  a section hader, you will see a hash symbol `#` at the end of the header, which contains the anchor link to this header. You can click on this link and get the URL in the addres bar of your web browser, or right-click on it and copy the URL from the context menu. The hash symbol is defined by the CSS rule `a.anchor-section::before {content: '#';}`. You can customize it by overriding this rule (e.g., via the `css` argument of `html_document`) and use any other symbols or icons, e.g., `content: "\02AD8;"` (thanks, @atusy, #1884).
 
+- `pkg_file_lua()` should have thrown an error if the expected Lua file does not exist.
+
 - Provide `files_dir` as attribute on return from `render()` when `run_pandoc = FALSE`.
 
 

R/util.R

@@ -63,9 +63,14 @@ pkg_file_arg <- function(..., package = "rmarkdown") {
 #' # get a specific filter
 #' pkg_file_lua(c("pagebreak.lua", "latex_div.lua"))
 pkg_file_lua <- function(filters = NULL, package = "rmarkdown") {
-  lua_folder <- pkg_file("rmarkdown", "lua", package = package, mustWork = TRUE)
-  if (is.null(filters)) filters <- list.files(lua_folder, "[.]lua$")
-  pandoc_path_arg(file.path(lua_folder, filters))
+  files <- pkg_file(
+    "rmarkdown", "lua", if (is.null(filters)) '.' else filters,
+    package = package, mustWork = TRUE
+  )
+  if (is.null(filters)) {
+    files <- list.files(dirname(files), "[.]lua$", full.names = TRUE)
+  }
+  pandoc_path_arg(files)
 }
 
 #' @rdname rmarkdown_format