fix rstudio/rmarkdown#2518: when fig.num is a multiple of fig.ncol, a…

…dd \newline to the last subfigure

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: knitr
 Type: Package
 Title: A General-Purpose Package for Dynamic Report Generation in R
-Version: 1.44.2
+Version: 1.44.3
 Authors@R: c(
     person("Yihui", "Xie", role = c("aut", "cre"), email = "[email protected]", comment = c(ORCID = "0000-0003-0645-5666")),
     person("Abhraneel", "Sarma", role = "ctb"),

NEWS.md

@@ -6,6 +6,8 @@
 
 - Negative numbers returned from inline R expressions lost their minus signs when formatted in the scientific notation (thanks, @fkohrt, #2288).
 
+- Add the necessary `\newline` to the last subfigure (thanks, @slrellison, rstudio/rmarkdown#2518).
+
 ## MAJOR CHANGES
 
 - `opts_current$set()` without `opts_current$lock(FALSE)` will trigger a warning instead of an error for now and it will become an error in future (#2296).

R/hooks-latex.R

@@ -80,7 +80,10 @@ hook_plot_tex = function(x, options) {
   fig.ncol = options$fig.ncol %n% fig.num
   if (is.null(fig.sep <- options$fig.sep)) {
     fig.sep = character(fig.num)
-    if (fig.ncol < fig.num) fig.sep[seq(fig.ncol, fig.num - 1L, fig.ncol)] = '\\newline'
+    # add \newline after every fig.ncol figures; if the last figure is not the
+    # last on its row, skip adding \newline (not necessary, but may be harmless)
+    if (fig.ncol < fig.num)
+      fig.sep[seq(fig.ncol, fig.num - (fig.num %% fig.ncol > 0), fig.ncol)] = '\\newline'
   }
   sep.cur = NULL