fix rstudio/bookdown#883: for LaTeX output in bookdown, do not write …

…<div class="environment"> for Pandoc >= 2.7.3, because such a div would be converted to a LaTeX environment

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.28.6
+Version: 1.28.7
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Adam", "Vogt", role = "ctb"),

NEWS.md

@@ -14,6 +14,8 @@
 
 - The chunk option `dpi` is correctly passed to `showtext::showtext_opts()` now (thanks, @cpsievert, yixuan/showtext#33).
 
+- Theorem environments in **bookdown** fail to work with Pandoc >= 2.7.3 because of an issue in the `block2` engine of **knitr** (rstudio/bookdown#883).
+
 ## MAJOR CHANGES
 
 - When a code chunk generates multiple plots to be placed in figure environments, their figure labels will be of the form `label-i` where `label` is the chunk label, and `i` is the plot number. Previously, the labels were of the form `labeli` (i.e., there was not a dash before the number). If you cross-reference the figures, you need to change the reference keys from `labeli` to `label-i`.

R/engine.R

@@ -455,10 +455,16 @@ eng_block2 = function(options) {
   h4 = options$html.after %n% ''
   h5 = options$html.before2 %n% ''
   h6 = options$html.after2 %n% ''
+  if (is_latex_output() && rmarkdown::pandoc_available('2.7.3')) {
+    h7 = h8 = '\n'
+  } else {
+    h7 = sprintf('<%s class="%s">', h2, type)
+    h8 = sprintf('</%s>', h2)
+  }
 
   sprintf(
-    '\\BeginKnitrBlock{%s}%s%s<%s class="%s">%s%s%s</%s>%s\\EndKnitrBlock{%s}',
-    type, l1, h3, h2, type, h5, code, h6, h2, h4, type
+    '\\BeginKnitrBlock{%s}%s%s%s%s%s%s%s%s\\EndKnitrBlock{%s}',
+    type, l1, h3, h7, h5, code, h6, h8, h4, type
   )
 }