[interchange] Ensure that we use a UTF8 locale for strftime in [convert-date] tag.

commit 8fd6ad78ee18174b556d953ca9ab52606b449acc
Author: Stefan Hornburg (Racke) <[email protected]>
Date:   Mon Mar 4 10:48:54 2013 +0100

    Ensure that we use a UTF8 locale for strftime in [convert-date] tag.
    Otherwise it causes a crash with "Malformed UTF-8 character".

 code/UserTag/convert_date.tag |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/code/UserTag/convert_date.tag b/code/UserTag/convert_date.tag
index e91b908..4718f81 100644
--- a/code/UserTag/convert_date.tag
+++ b/code/UserTag/convert_date.tag
@@ -76,7 +76,13 @@ sub {
 	my $locale = $opt->{locale} || $Scratch->{mv_locale};
 	if ($locale) {
 		$current = POSIX::setlocale(&POSIX::LC_TIME);
-		POSIX::setlocale(&POSIX::LC_TIME, $locale);
+        if (($::Variable->{MV_UTF8} || $Global::Variable->{MV_UTF8})
+            && $locale !~ /\.utf8$/) {
+            POSIX::setlocale(&POSIX::LC_TIME, "$locale.utf8");
+        }
+        else {
+            POSIX::setlocale(&POSIX::LC_TIME, $locale);
+        }
 		$out = POSIX::strftime($fmt, @t);
 		POSIX::setlocale(&POSIX::LC_TIME, $current);
 	} else {