don't attempt to force UTF-8 but print warning if we aren't in UTF-8

src/cpp/session/SessionMain.cpp

@@ -157,9 +157,6 @@ bool s_rSessionResumed = false;
 // manage global state indicating whether R is processing input
 volatile sig_atomic_t s_rProcessingInput = 0;
 
-// did we fail to coerce the charset to UTF-8
-bool s_printCharsetWarning = false;
-
 std::queue<r::session::RConsoleInput> s_consoleInputBuffer;
 
 // superivsor is a module level static so that we can terminateChildren
@@ -1304,6 +1301,16 @@ Error runPreflightScript()
    // always return success
    return Success();
 }
+
+bool usingUTF8Charset()
+{
+   bool usingUTF8 = false;
+   Error error = r::exec::RFunction(".rs.usingUtf8Charset").call(&usingUTF8);
+   if (error)
+      LOG_ERROR(error);
+
+   return usingUTF8;
+}
 
 Error rInit(const r::session::RInitInfo& rInitInfo) 
 {
@@ -1424,8 +1431,10 @@ Error rInit(const r::session::RInitInfo& rInitInfo)
       session::clientEventQueue().add(abendWarningEvent);
    }
 
-   if (s_printCharsetWarning)
+#ifndef _WIN32
+   if (!usingUTF8Charset())
       r::exec::warning("Character set is not UTF-8; please change your locale");
+#endif
 
    // propagate console history options
    r::session::consoleHistory().setRemoveDuplicates(
@@ -2363,76 +2372,6 @@ int sessionExitFailure(const core::Error& cause,
    return EXIT_FAILURE;
 }
 
-std::string ctypeEnvName()
-{
-   if (!core::system::getenv("LC_ALL").empty())
-      return "LC_ALL";
-   if (!core::system::getenv("LC_CTYPE").empty())
-      return "LC_CTYPE";
-   if (!core::system::getenv("LANG").empty())
-      return "LANG";
-   return "LC_CTYPE";
-}
-
-/*
-If possible, we want to coerce the character set to UTF-8.
-We can't do this by directly calling setlocale because R
-will override those settings when it starts up. Instead we
-set the corresponding environment variables, which R will
-use.
-
-The exception is Win32, which doesn't allow UTF-8 to be used
-as an ANSI codepage.
-
-Returns false if we tried and failed to set the charset to
-UTF-8, either because we didn't recognize the locale string
-format or because the system didn't accept our new locale
-string.
-*/
-bool ensureUtf8Charset()
-{
-#if _WIN32
-   return true;
-#else
-   std::string charset(locale2charset(NULL));
-   if (charset == "UTF-8")
-      return true;
-
-   std::string name = ctypeEnvName();
-   std::string ctype = core::system::getenv(name);
-
-   std::string newCType;
-   if (ctype.empty() || ctype == "C" || ctype == "POSIX")
-   {
-      newCType = "en_US.UTF-8";
-   }
-   else
-   {
-      using namespace boost;
-
-      smatch match;
-      if (regex_match(ctype, match, regex("(\\w+_\\w+)(\\.[^@]+)?(@.+)?")))
-      {
-         // Try to replace the charset while keeping everything else the same.
-         newCType = match[1] + ".UTF-8" + match[3];
-      }
-   }
-
-   if (!newCType.empty())
-   {
-      if (setlocale(LC_CTYPE, newCType.c_str()))
-      {
-         core::system::setenv(name, newCType);
-         setlocale(LC_CTYPE, "");
-         return true;
-      }
-   }
-
-   return false;
-#endif
-}
-
-
 } // anonymous namespace
 
 // run session
@@ -2455,9 +2394,6 @@ int main (int argc, char * const argv[])
       // from the main thread vs. child threads)
       s_mainThreadId = boost::this_thread::get_id();
 
-      // determine character set
-      s_printCharsetWarning = !ensureUtf8Charset();
-
       // read program options
       Options& options = session::options();
       ProgramStatus status = options.read(argc, argv) ;

src/cpp/session/modules/ModuleTools.R

@@ -70,3 +70,8 @@
          return ("")
    }
 })
+
+.rs.addFunction("usingUtf8Charset", function()
+{
+   l10n_info()$`UTF-8` || identical(utils::localeToCharset(), "UTF-8")
+})