fix rstudio/rmarkdown#1721: use the meta variable has-frontmatter=false to disable the automatic addition of \frontmatter, \mainmatter, and \backmatter

yihui · yihui · commit 51e7ff18097b · 2019-12-05T00:01:20.000-06:00
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: bookdown
 Type: Package
 Title: Authoring Books and Technical Documents with R Markdown
-Version: 0.16.2
+Version: 0.16.3
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("JJ", "Allaire", role = "ctb"),
@@ -78,5 +78,5 @@ URL: https://github.com/rstudio/bookdown
 BugReports: https://github.com/rstudio/bookdown/issues
 SystemRequirements: Pandoc (>= 1.17.2)
 LazyData: TRUE
-RoxygenNote: 7.0.1
+RoxygenNote: 7.0.2
 Encoding: UTF-8
diff --git a/NEWS.md b/NEWS.md
@@ -8,6 +8,8 @@
 
 - For output formats like `pdf_book`, unused arguments passed to `base_format` will be discarded (thanks, @jooyoungseo, #790).
 
+- For the sake of backward-compatibility, prevent the commands `\frontmatter`, `\mainmatter`, and `\backmatter` from being automatically added to the LaTeX output when the Pandoc version is higher than 2.7, because **bookdown** users may have added these commands by themselves (thanks, @remlapmot, rstudio/rmarkdown#1721).
+
 ## MINOR CHANGES
 
 - The default value of `base_format` in the `markdown_document2` format is `rmarkdown::md_document` now. Previously the default value is missing.
diff --git a/R/latex.R b/R/latex.R
@@ -80,7 +80,10 @@ pdf_book = function(
   # always enable tables (use packages booktabs, longtable, ...)
   pre = config$pre_processor
   config$pre_processor = function(...) {
-    c(if (is.function(pre)) pre(...), '--variable', 'tables=yes', '--standalone')
+    c(
+      if (is.function(pre)) pre(...), '--variable', 'tables=yes', '--standalone',
+      if (rmarkdown::pandoc_available('2.7.1')) '-Mhas-frontmatter=false'
+    )
   }
   config$bookdown_output_format = 'latex'
   config = set_opts_knit(config)
