--- loncom/localize/lonlocal.pm	2009/02/01 21:54:30	1.54
+++ loncom/localize/lonlocal.pm	2009/10/01 20:22:33	1.60
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Localization routines
 #
-# $Id: lonlocal.pm,v 1.54 2009/02/01 21:54:30 lueken Exp $
+# $Id: lonlocal.pm,v 1.60 2009/10/01 20:22:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -173,16 +173,14 @@ require Exporter;
 our @ISA = qw (Exporter);
 our @EXPORT = qw(mt mtn ns mt_user);
 
+my %mtcache=();
+
 # ========================================================= The language handle
 
-use vars qw($lh);
+use vars qw($lh $current_language);
 
 # ===================================================== The "MakeText" function
 
-######### Localize Cache
-my @localize_cache;
-#########
-
 sub mt (@) {
 #    open(LOG,'>>/home/www/loncapa/loncom/localize/localize/newphrases.txt');
 #    print LOG (@_[0]."\n");
@@ -195,18 +193,13 @@ sub mt (@) {
                 return $_[0];
             }
         } else {
-				######### Localize Cache
-				foreach my $e (@localize_cache)
-				{
-					if($_[0] eq $$e[0]) { return $$e[1]; }
-				}
-
-				if($#localize_cache == 100) { pop(@localize_cache); }
-				my $localize_entry = $lh->maketext(@_);
-				unshift(@localize_cache, [ @_, $localize_entry ] );
-				#########
-            
-	    		return $localize_entry;
+            if ($#_>0) { return $lh->maketext(@_); }
+            if ($mtcache{$current_language.':'.$_[0]}) {
+               return $mtcache{$current_language.':'.$_[0]};
+            }
+            my $translation=$lh->maketext(@_);
+            $mtcache{$current_language.':'.$_[0]}=$translation;
+            return $translation; 
         }
     } else {
 	if (wantarray) {
@@ -269,8 +262,8 @@ sub preferred_languages {
         push(@languages,@browser);
     }
 
-    foreach my $domtype ($Apache::lonnet::env{'user.domain'},$Apache::lonnet::env{'request.role.domain'},
-                         $Apache::lonnet::perlvar{'lonDefDomain'}) {
+    my $defdom = &Apache::lonnet::default_login_domain();
+    foreach my $domtype ($Apache::lonnet::env{'user.domain'},$Apache::lonnet::env{'request.role.domain'},$defdom) {
         if ($domtype ne '') {
             my %domdefs = &Apache::lonnet::get_domain_defaults($domtype);
             if ($domdefs{'lang_def'} ne '') {
@@ -302,10 +295,13 @@ sub get_genlanguages {
 
 sub current_encoding {
     my $default='UTF-8';
-    if ($Apache::lonnet::env{'browser.os'} eq 'win' && 
-	$Apache::lonnet::env{'browser.type'} eq 'explorer') {
-        $default='ISO-8859-1';
-    }
+# UTF-8 character encoding needed for the whole LON-CAPA system
+# (interface language and homework problem content)
+# See Bugzilla 5702 vs. 2189 and 4067
+#    if ($Apache::lonnet::env{'browser.os'} eq 'win' && 
+#	$Apache::lonnet::env{'browser.type'} eq 'explorer') {
+#        $default='ISO-8859-1';
+#    }
     if ($lh) {
 	my $enc=$lh->maketext('char_encoding');
 	return ($enc eq 'char_encoding'?$default:$enc);
@@ -347,6 +343,7 @@ sub get_language_handle {
     my @languages=&preferred_languages();
     $ENV{'HTTP_ACCEPT_LANGUAGE'}='';
     $lh=Apache::localize->get_handle(@languages);
+    $current_language=&current_language();
     if ($r) {
 	$r->content_languages([&current_language()]);
     }
@@ -398,6 +395,7 @@ sub gettimezone {
 
 sub locallocaltime {
     my ($thistime,$timezone) = @_;
+
     if (!defined($thistime) || $thistime eq '') {
 	return &mt('Never');
     }
@@ -411,7 +409,16 @@ sub locallocaltime {
     }
 
     my $dt = DateTime->from_epoch(epoch => $thistime)
-                     ->set_time_zone(&gettimezone($timezone));
+                     ->set_time_zone(gettimezone($timezone));
+
+    # TimeZone tries to determine the 'local' timezone from $ENV{TZ} if this
+    # fails it searches through various system files. Under certain
+    # circumstances this is an extremly expensive operation.
+    # So after the first run we store the timezone in $ENV{TZ} to significantly
+    # speed up future lookups. 
+    $ENV{TZ} = $dt->time_zone()->name() 
+        if (! $ENV{TZ} && gettimezone($timezone) eq 'local');
+
     if ((&current_language=~/^en/) || (!$lh)) {
 
 	return $dt->strftime("%a %b %e %I:%M:%S %P %Y (%Z)");