MiKTeX nowadays respects TEXINPUTS

git-svn-id: https://svn.r-project.org/R/trunk@87699 00db46b3-68df-0310-9c12-caf00c1e9a41

doc/manual/R-intro.texi

@@ -7220,9 +7220,9 @@ R CMD latex.exe mydoc
 @end example
 @noindent
 will run @LaTeX{} on @file{mydoc.tex}, with the path to @R{}'s
-@file{share/texmf} macros appended to @env{TEXINPUTS}.  (Unfortunately,
-this does not help with the @I{MiKTeX} build of @LaTeX{}, but
-@command{R CMD texify mydoc} will work in that case.)
+@file{share/texmf} macros appended to @env{TEXINPUTS}.
+(With the @I{MiKTeX} build of @LaTeX{}, using
+@command{R CMD texify mydoc} is often more convenient.)
 
 @node Invoking R under macOS
 @appendixsec Invoking R under macOS

src/library/base/man/Sys.which.Rd

@@ -48,7 +48,7 @@ Sys.which(names)
 }
 \examples{
 ## the first two are likely to exist everywhere
-## texi2dvi exists on most Unix-alikes and under MiKTeX
+## texi2dvi exists on most Unix-alikes but not under MiKTeX
 Sys.which(c("ftp", "ping", "texi2dvi", "this-does-not-exist"))
 }
 \keyword{ utilities }

src/library/tools/R/utils.R

@@ -444,17 +444,15 @@ function(file, pdf = FALSE, clean = FALSE, quiet = TRUE,
         extra <- ""
 
         ## look for MiKTeX (which this almost certainly is)
-        ## and set the path to R's style files.
-        ## -I works in MiKTeX >= 2.4, at least
         ## http://docs.miktex.org/manual/texify.html
-        ## FIXME: is -I still needed? It documents EnvVars since at least 2016.
         ver <- system(paste(shQuote(texi2dvi), "--version"), intern = TRUE)
         if(length(grep("MiKTeX", ver[1L]))) {
-            ## AFAICS need separate -I for each element of texinputs.
-            texinputs <- c(texinputs, Rtexinputs, Rbstinputs)
-            paths <- paste ("-I", shQuote(texinputs))
             extra <- "--max-iterations=20"
-            extra <- paste(extra, paste(paths, collapse = " "))
+            ## setting TEXINPUTS via -I is long obsolete, EnvVars are respected
+            ## (<https://docs.miktex.org/manual/localadditions.html>)
+            ##   texinputs <- c(texinputs, Rtexinputs, Rbstinputs)
+            ##   paths <- paste ("-I", shQuote(texinputs))
+            ##   extra <- paste(extra, paste(paths, collapse = " "))
         }
         ## 'file' could be a file path
         base <- basename(file_path_sans_ext(file))