fix rstudio#790: make sure unused arguments are discarded when they are passed to the base format

yihui · yihui · commit 687b672008c5 · 2019-11-26T15:47:30.000-06:00
diff --git a/NEWS.md b/NEWS.md
@@ -1,6 +1,8 @@
 # CHANGES IN bookdown VERSION 0.17
 
+## BUG FIXES
 
+- For output formats like `pdf_book`, unused arguments passed to `base_format` will be discarded (thanks, @jooyoungseo, #790).
 
 # CHANGES IN bookdown VERSION 0.16
 
diff --git a/R/html.R b/R/html.R
@@ -54,12 +54,11 @@ html_chapters = function(
   base_format = rmarkdown::html_document, split_bib = TRUE, page_builder = build_chapter,
   split_by = c('section+number', 'section', 'chapter+number', 'chapter', 'rmd', 'none')
 ) {
-  base_format = get_base_format(base_format)
-  config = base_format(
+  config = get_base_format(base_format, list(
     toc = toc, number_sections = number_sections, fig_caption = fig_caption,
     self_contained = FALSE, lib_dir = lib_dir,
     template = template, pandoc_args = pandoc_args2(pandoc_args), ...
-  )
+  ))
   split_by = match.arg(split_by)
   post = config$post_processor  # in case a post processor have been defined
   config$post_processor = function(metadata, input, output, clean, verbose) {
@@ -126,10 +125,9 @@ tufte_html_book = function(...) {
 html_document2 = function(
   ..., number_sections = TRUE, pandoc_args = NULL, base_format = rmarkdown::html_document
 ) {
-  base_format = get_base_format(base_format)
-  config = base_format(
+  config = get_base_format(base_format, list(
     ..., number_sections = number_sections, pandoc_args = pandoc_args2(pandoc_args)
-  )
+  ))
   post = config$post_processor  # in case a post processor have been defined
   config$post_processor = function(metadata, input, output, clean, verbose) {
     if (is.function(post)) output = post(metadata, input, output, clean, verbose)
diff --git a/R/latex.R b/R/latex.R
@@ -36,11 +36,10 @@ pdf_book = function(
   base_format = rmarkdown::pdf_document, toc_unnumbered = TRUE,
   toc_appendix = FALSE, toc_bib = FALSE, quote_footer = NULL, highlight_bw = FALSE
 ) {
-  base_format = get_base_format(base_format)
-  config = base_format(
+  config = get_base_format(base_format, list(
     toc = toc, number_sections = number_sections, fig_caption = fig_caption,
     pandoc_args = pandoc_args2(pandoc_args), ...
-  )
+  ))
   config$pandoc$ext = '.tex'
   post = config$post_processor  # in case a post processor have been defined
   config$post_processor = function(metadata, input, output, clean, verbose) {
diff --git a/R/utils.R b/R/utils.R
@@ -34,12 +34,14 @@ set_opts_knit = function(config) {
   config
 }
 
-get_base_format = function(format) {
-  if (is.character(format)) {
-    format = eval(parse(text = format))
-  }
+get_base_format = function(format, options = list()) {
+  if (is.character(format)) format = eval(parse(text = format))
   if (!is.function(format)) stop('The output format must be a function')
-  format
+  # make sure named elements in `options` have corresponding named arguments in
+  # the format function, unless the function has the ... argument
+  nms = names(formals(format))
+  if (!('...' %in% nms)) options = options[names(options) %in% c(nms, '')]
+  do.call(format, options)
 }
 
 load_config = function() {
diff --git a/R/word.R b/R/word.R
@@ -5,10 +5,9 @@ markdown_document2 = function(
 ) {
   from = rmarkdown::from_rmarkdown(fig_caption, md_extensions)
 
-  base_format = get_base_format(base_format)
-  config = base_format(
+  config = get_base_format(base_format, list(
     fig_caption = fig_caption, md_extensions = md_extensions, pandoc_args = pandoc_args, ...
-  )
+  ))
   pre = config$pre_processor
   config$pre_processor = function(metadata, input_file, ...) {
     # Pandoc does not support numbered sections for Word, so figures/tables have
