do not warn but message, when Sys.setLanguage("en") is deficient in C…

… locale

git-svn-id: https://svn.r-project.org/R/trunk@87051 00db46b3-68df-0310-9c12-caf00c1e9a41

doc/NEWS.Rd

@@ -255,7 +255,8 @@
  \PR{15027}.
 
  \item \code{Sys.setLanguage()} now works in an \command{LC_ALL=C R} session
- on some platforms.
+ on some platforms, warns about \emph{some} failures to change the
+ language and gets an option related to these warning messages.
 
  \item Printing \code{ls.str()} now tries harder to show
  \code{"<missing>"} even when \R's language setting is not English.

src/library/base/R/stop.R

@@ -126,27 +126,30 @@ gettextf <- function(fmt, ..., domain = NULL, trim = TRUE)
 
 ## Could think of using *several* domains, i.e. domain = vector; but seems complicated;
 ## the default domain="R" seems to work for all of base R: {"R", "R-base", "RGui"}
-Sys.setLanguage <- function(lang, unset = "en")
+Sys.setLanguage <- function(lang, unset = "en", allowC4en = TRUE)
 {
  if (!capabilities("NLS") || is.na(.popath)) {
  warning(gettextf("no natural language support or missing translations"), domain=NA)
- return(invisible(""))
+ return(invisible(structure("", ok = FALSE)))
  }
  stopifnot(is.character(lang), length(lang) == 1L, # e.g., "es" , "fr_CA"
  lang == "C" || grepl("^[a-z][a-z]", lang))
  curLang <- Sys.getenv("LANGUAGE", unset = NA) # so it can be reset
  if(is.na(curLang) || !nzchar(curLang))
  curLang <- unset # "factory" default
- if(isC <- identical("C", Sys.getlocale())) { ## e.g. LC_ALL=C R on Linux
+ Warning <- if(allowC4en && startsWith(lang, "en")) message else warning
+ if(identical("C", Sys.getlocale()) && lang != "C") { ## e.g. LC_ALL=C R on Linux
  lcSet <- if(.Platform[["OS.type"]] == "unix")
  Sys.setlocale("LC_MESSAGES", "en_US.UTF-8")
- ## TODOs: 1) does en_US.UTF-8 always exist? 2) need to deal w/ Windows ?
+ ## TODOs: 1) does en_US.UTF-8 always exist?
+ ## 2) How to deal w/ Windows ? {can set things but with *no* effect}
  ok.lc <- !is.null(lcSet) && nzchar(lcSet) # NULL or "" are not ok
- if(!ok.lc) warning(gettextf("In a bare C locale, could not change language"), domain=NA)
+ if(!ok.lc)
+ Warning(gettextf("In a bare C locale, could not change language"), domain=NA)
  } else ok.lc <- TRUE
  ok <- Sys.setenv(LANGUAGE=lang)
  if(!ok)
- warning(gettextf('Sys.setenv(LANGUAGE="%s") may have failed', lang), domain=NA)
+ Warning(gettextf('Sys.setenv(LANGUAGE="%s") may have failed', lang), domain=NA)
  ok. <- capabilities("NLS") &&
  isTRUE(bindtextdomain(NULL)) # only flush the cache (of already translated strings)
  invisible(structure(curLang, ok = ok && ok.lc && ok.))

src/library/base/man/gettext.Rd

@@ -1,6 +1,6 @@
 % File src/library/base/man/gettext.Rd
 % Part of the R package, https://www.R-project.org
-% Copyright 1995-2023 R Core Team
+% Copyright 1995-2024 R Core Team
 % Distributed under GPL 2 or later
 
 \name{gettext}
@@ -27,7 +27,7 @@ ngettext(n, msg1, msg2, domain = NULL)
 
 bindtextdomain(domain, dirname = NULL)
 
-Sys.setLanguage(lang, unset = "en")
+Sys.setLanguage(lang, unset = "en", allowC4en = TRUE)
 }
 \arguments{
  \item{\dots}{one or more character vectors.}
@@ -46,6 +46,9 @@ Sys.setLanguage(lang, unset = "en")
  \item{unset}{a string, specifying the default language assumed to be
  current in the case \code{\link{Sys.getenv}("LANGUAGE")} is unset or
  empty.}
+ \item{allowC4en}{logical indicating if a current (sometimes \dQuote{hard})
+ setting of language \code{"C"} is acceptable for \code{lang = "en"}. In that
+ case, \code{\link{message}()} is called instead of \code{\link{warning}()}.}
 }
 \details{
  If \code{domain} is \code{NULL} (the default) in \code{gettext}
@@ -70,7 +73,7 @@ Sys.setLanguage(lang, unset = "en")
 
  The \emph{language} to be used for message translation is determined by
  your OS default and/or the locale setting at \R's startup, see
- \code{\link{Sys.getlocale}()}, and notably the \env{LANGUAGE} environment 
+ \code{\link{Sys.getlocale}()}, and notably the \env{LANGUAGE} environment
  variable, and also \code{Sys.setLanguage()} here.
 
  Conventionally the domain for \R warning/error messages in package