--- rat/lonuserstate.pm	2007/06/28 23:26:38	1.118.2.2
+++ rat/lonuserstate.pm	2009/11/16 20:26:04	1.128.2.3
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Construct and maintain state and binary representation of course for user
 #
-# $Id: lonuserstate.pm,v 1.118.2.2 2007/06/28 23:26:38 albertel Exp $
+# $Id: lonuserstate.pm,v 1.128.2.3 2009/11/16 20:26:04 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -109,7 +109,9 @@ sub processversionfile {
 sub loadmap { 
     my ($uri,$parent_rid)=@_;
     if ($hash{'map_pc_'.$uri}) { 
-	$errtext.=&mt('<br />Multiple use of sequence/page <tt>[_1]</tt>! The course will not function properly.',$uri);
+	$errtext.='<p class="LC_error">'.
+	    &mt('Multiple use of sequence/page [_1]! The course will not function properly.','<tt>'.$uri.'</tt>').
+	    '</p>';
 	return; 
     }
     $pc++;
@@ -174,13 +176,23 @@ sub loadmap {
     }
 
     if ($randomize) {
-	my $seed = (split(/\./,$parent_rid))[1];
-	if ($randompickseed{$parent_rid}) {
-	    $seed = $randompickseed{$parent_rid};
+	if (!$env{'request.role.adv'}) {
+	    my $seed;
+	    if (defined($randompickseed{$parent_rid})) {
+		$seed = $randompickseed{$parent_rid};
+	    } else {
+		my ($mapid,$resid)=split(/\./,$parent_rid);
+		my $symb=
+		    &Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
+						 $resid,$hash{'src_'.$parent_rid});
+		
+		$seed = $symb;
+	    }
+	
+	    my $rndseed=&Apache::lonnet::rndseed($seed);
+	    &Apache::lonnet::setup_random_from_rndseed($rndseed);
+	    @map_ids=&Math::Random::random_permutation(@map_ids);
 	}
-	my $rndseed=&Apache::lonnet::rndseed($seed);
-	&Apache::lonnet::setup_random_from_rndseed($rndseed);
-	my @map_ids=&Math::Random::random_permutation(@map_ids);
 	my $from = shift(@map_ids);
 	my $from_rid = $lpc.'.'.$from;
 	$hash{'map_start_'.$uri} = $from_rid;
@@ -197,6 +209,17 @@ sub loadmap {
 	$hash{'map_finish_'.$uri}= $from_rid;
 	$hash{'type_'.$from_rid}='finish';
     }
+
+    $parser = HTML::TokeParser->new(\$instr);
+    $parser->attr_encoded(1);
+    # last parse out the mapalias params so as to ignore anything
+    # refering to non-existant resources
+    while (my $token = $parser->get_token) {
+	next if ($token->[0] ne 'S');
+	if ($token->[1] eq 'param') {
+	    &parse_mapalias_param($token,$lpc);
+	} 
+    }
 }
 
 
@@ -224,7 +247,7 @@ sub parse_resource {
 	$turi=~/\.(\w+)$/;
 	my $embstyle=&Apache::loncommon::fileembstyle($1);
 	if ($token->[2]->{'external'} eq 'true') { # external
-	    $turi=~s/^http\:\/\//\/adm\/wrapper\/ext\//;
+	    $turi=~s/^https?\:\/\//\/adm\/wrapper\/ext\//;
 	} elsif ($turi=~/^\/*uploaded\//) { # uploaded
 	    if (($embstyle eq 'img') 
 		|| ($embstyle eq 'emb')
@@ -320,7 +343,10 @@ sub parse_condition {
     my $rid=$lpc.'.'.$token->[2]->{'id'};
     
     $hash{'kind_'.$rid}='cond';
-    $cond[$#cond+1]=$token->[2]->{'value'};
+
+    my $condition = $token->[2]->{'value'};
+    $condition =~ s/[\n\r]+/ /gs;
+    push(@cond, $condition);
     $hash{'condid_'.$rid}=$#cond;
     if ($token->[2]->{'type'}) {
 	$cond[$#cond].=':'.$token->[2]->{'type'};
@@ -351,9 +377,6 @@ sub parse_param {
     } else {
 	$hash{'param_'.$referid}=''.$newparam;
     }
-    if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
-	$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
-    }
     if ($token->[2]->{'name'}=~/^parameter_(0_)*randompick$/) {
 	$randompick{$referid}=$token->[2]->{'value'};
     }
@@ -362,7 +385,6 @@ sub parse_param {
     }
     if ($token->[2]->{'name'}=~/^parameter_(0_)*randomorder$/) {
 	$randomorder{$referid}=$token->[2]->{'value'};
-	&Apache::lonnet::logthis("roing $referid ".$randomorder{$referid});
     }
     if ($token->[2]->{'name'}=~/^parameter_(0_)*encrypturl$/) {
 	if ($token->[2]->{'value'}=~/^yes$/i) {
@@ -376,6 +398,17 @@ sub parse_param {
     }
 }
 
+sub parse_mapalias_param {
+    my ($token,$lpc) = @_;
+    my $referid=$lpc.'.'.$token->[2]->{'to'};
+    return if (!exists($hash{'src_'.$referid}));
+
+    if ($token->[2]->{'name'}=~/^parameter_(0_)*mapalias$/) {
+	&count_mapalias($token->[2]->{'value'},$referid);
+	$hash{'mapalias_'.$token->[2]->{'value'}}=$referid;
+    }
+}
+
 # --------------------------------------------------------- Simplify expression
 
 sub simplify {
@@ -404,7 +437,7 @@ sub simplify {
 sub traceroute {
     my ($sofar,$rid,$beenhere,$encflag,$hdnflag)=@_;
     my $newsofar=$sofar=simplify($sofar);
-    unless ($beenhere=~/\&$rid\&/) {
+    unless ($beenhere=~/\&\Q$rid\E\&/) {
 	$beenhere.=$rid.'&';  
 	my ($mapid,$resid)=split(/\./,$rid);
 	my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$rid});
@@ -438,7 +471,8 @@ sub traceroute {
 	    if (defined($hash{'map_start_'.$hash{'src_'.$rid}})) {
 		$sofar=$newsofar=
 		    &traceroute($sofar,
-				$hash{'map_start_'.$hash{'src_'.$rid}},'&',
+				$hash{'map_start_'.$hash{'src_'.$rid}},
+				$beenhere,
 				$encflag || $encurl{$rid},
 				$hdnflag || $hiddenurl{$rid});
 	    }
@@ -539,8 +573,9 @@ sub accinit {
     $acchash{'acc.res.'.$short.'.'}='&:0&';
     my $courseuri=$uri;
     $courseuri=~s/^\/res\///;
-    &Apache::lonnet::delenv('(acc\.|httpref\.)');
-    &Apache::lonnet::appenv(%acchash);
+    my $regexp = 1;
+    &Apache::lonnet::delenv('(acc\.|httpref\.)',$regexp);
+    &Apache::lonnet::appenv(\%acchash);
 }
 
 # ---------------- Selectively delete from randompick maps and hidden url parms
@@ -596,7 +631,7 @@ sub hiddenurls {
     }
 # --------------------------------------- append randomout entry to environment
     if ($randomoutentry) {
-	&Apache::lonnet::appenv('acc.randomout' => $randomoutentry);
+	&Apache::lonnet::appenv({'acc.randomout' => $randomoutentry});
     }
 }
 
@@ -610,90 +645,52 @@ sub readmap {
     my $uri;
     $short=~s/\//\_/g;
     unless ($uri=$cenv{'url'}) { 
-	&Apache::lonnet::logthis("<font color=blue>WARNING: ".
+	&Apache::lonnet::logthis('<font color="blue">WARNING: '.
 				 "Could not load course $short.</font>"); 
 	return ('',&mt('No course data available.'));;
     }
     @cond=('true:normal');
 
-    open(LOCKFILE,">$fn.db.lock");
+    unless (open(LOCKFILE,">$fn.db.lock")) {
+        $errtext.='<br />'.&mt('Map not loaded - Lock file could not be opened when reading map:').' <tt>'.$fn.'</tt>.';
+        $retfurl = '';
+        return ($retfurl,$errtext);
+    }
     my $lock=0;
+    my $gotstate=0;
     if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
 	$lock=1;
-	unlink($fn.'.db');
-	unlink($fn.'_symb.db');
-	unlink($fn.'.state');
-	unlink($fn.'parms.db');
+        &unlink_tmpfiles($fn);
     }
     undef %randompick;
     undef %hiddenurl;
     undef %encurl;
     $retfrid='';
-    if ($lock && (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) &&
-	(tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640))) {
-	%hash=();
-	%parmhash=();
-	$errtext='';
-	$pc=0;
-	&processversionfile(%cenv);
-	my $furi=&Apache::lonnet::clutter($uri);
-	$hash{'src_0.0'}=&versiontrack($furi);
-	$hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
-	$hash{'ids_'.$furi}='0.0';
-	$hash{'is_map_0.0'}=1;
-	loadmap($uri,'0.0');
-	if (defined($hash{'map_start_'.$uri})) {
-	    &Apache::lonnet::appenv("request.course.id"  => $short,
-				    "request.course.fn"  => $fn,
-				    "request.course.uri" => $uri);
-	    $env{'request.course.id'}=$short;
-	    &traceroute('0',$hash{'map_start_'.$uri},'&');
-	    &accinit($uri,$short,$fn);
-	    &hiddenurls();
-	}
-# ------------------------------------------------------- Put versions into src
-	foreach my $key (keys(%hash)) {
-	    if ($key=~/^src_/) {
-		$hash{$key}=&putinversion($hash{$key});
-	    } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
-		my ($type, $url) = ($1,$2);
-		my $value = $hash{$key};
-		$hash{$type.&putinversion($url)}=$value;
-	    }
-	}
-# ---------------------------------------------------------------- Encrypt URLs
-	foreach my $id (keys(%encurl)) {
-#	    $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
-	    $hash{'encrypted_'.$id}=1;
-	}
-# ----------------------------------------------- Close hashes to finally store
-# --------------------------------- Routine must pass this point, no early outs
-	$hash{'first_rid'}=$retfrid;
-	my ($mapid,$resid)=split(/\./,$retfrid);
-	$hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
-	my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
-	$retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
-	if ($hash{'encrypted_'.$retfrid}) {
-	    $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
-	}
-	$hash{'first_url'}=$retfurl;
-	unless ((untie(%hash)) && (untie(%parmhash))) {
-	    &Apache::lonnet::logthis("<font color=blue>WARNING: ".
-				     "Could not untie coursemap $fn for $uri.</font>"); 
-	}
-# ---------------------------------------------------- Store away initial state
-	{
-	    my $cfh;
-	    if (open($cfh,">$fn.state")) {
-		print $cfh join("\n",@cond);
-	    } else {
-		&Apache::lonnet::logthis("<font color=blue>WARNING: ".
-					 "Could not write statemap $fn for $uri.</font>"); 
-	    }
-	}
-	flock(LOCKFILE,LOCK_UN);
-	close(LOCKFILE);
-    } else {
+    my ($untiedhash,$untiedparmhash,$tiedhash,$tiedparmhash);
+    if ($lock) {
+        if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
+            $tiedhash = 1;
+            if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
+                $tiedparmhash = 1;
+                $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv);
+                unless ($gotstate) {
+                    &Apache::lonnet::logthis('Failed to write statemap at first attempt '.$fn.' for '.$uri.'.</font>');
+                }
+                $untiedparmhash = untie(%parmhash);
+                unless ($untiedparmhash) {
+                    &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                        'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
+                }
+            }
+            $untiedhash = untie(%hash);
+            unless ($untiedhash) {
+                &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                    'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
+            }
+        }
+        flock(LOCKFILE,LOCK_UN);
+    }
+    unless ($lock && $tiedhash && $tiedparmhash) {
 	# if we are here it is likely because we are already trying to 
 	# initialize the course in another child, busy wait trying to 
 	# tie the hashes for the next 90 seconds, if we succeed forward 
@@ -702,34 +699,113 @@ sub readmap {
 	if ($lock) {
 	    # Got the lock but not the DB files
 	    flock(LOCKFILE,LOCK_UN);
+            $lock = 0;
 	}
-	untie(%hash);
-	untie(%parmhash);
-	&Apache::lonnet::logthis("<font color=blue>WARNING: ".
-				 "Could not tie coursemap $fn for $uri.</font>"); 
+        if ($tiedhash) {
+            unless($untiedhash) {
+                untie(%hash);
+            }
+        }
+        if ($tiedparmhash) {
+            unless($untiedparmhash) {
+                untie(%parmhash);
+            }
+        }
+        &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                                 "Could not tie coursemap $fn for $uri.</font>");
+        $tiedhash = '';
+        $tiedparmhash = '';
 	my $i=0;
 	while($i<90) {
 	    $i++;
 	    sleep(1);
-	    if (flock(LOCKFILE,LOCK_EX|LOCK_NB) &&
-		(tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640))) {
-		if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
-		    $retfurl='/adm/navmaps';
-		    &Apache::lonnet::appenv("request.course.id"  => $short,
-					    "request.course.fn"  => $fn,
-					    "request.course.uri" => $uri);
-		    untie(%hash);
-		    untie(%parmhash);
-		    last;
+	    if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
+                $lock = 1;
+		if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_READER(),0640)) {
+                    $tiedhash = 1;
+		    if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_READER(),0640)) {
+                        $tiedparmhash = 1;
+                        if (-e "$fn.state") {
+		            $retfurl='/adm/navmaps';
+		            &Apache::lonnet::appenv({"request.course.id"  => $short,
+					             "request.course.fn"  => $fn,
+					             "request.course.uri" => $uri});
+                            $untiedhash = untie(%hash);
+                            $untiedparmhash = untie(%parmhash);
+                            $gotstate = 1;
+		            last;
+                        }
+                        $untiedparmhash = untie(%parmhash);
+                    }
+                    $untiedhash = untie(%hash);
 		}
 	    }
-	    untie(%hash);
-	    untie(%parmhash);
 	}
-	flock(LOCKFILE,LOCK_UN);
-	close(LOCKFILE);
+        if ($lock) {
+            flock(LOCKFILE,LOCK_UN);
+            $lock = 0;
+            if ($tiedparmhash) {
+                unless ($untiedparmhash) {
+                    &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                        'Could not untie coursemap parmhash '.$fn.' for '.$uri.'.</font>');
+                }
+            }
+            if ($tiedparmhash) {
+                unless ($untiedhash) {
+                    &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                        'Could not untie coursemap hash '.$fn.' for '.$uri.'.</font>');
+                }
+            }
+        }
+    }
+    unless ($gotstate) {
+        $lock = 0;
+        &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                     'Could not read statemap '.$fn.' for '.$uri.'.</font>');
+        &unlink_tmpfiles($fn);
+        if (flock(LOCKFILE,LOCK_EX|LOCK_NB)) {
+            $lock=1;
+        }
+        undef %randompick;
+        undef %hiddenurl;
+        undef %encurl;
+        $retfrid='';
+        if ($lock) {
+            if (tie(%hash,'GDBM_File',"$fn.db",&GDBM_WRCREAT(),0640)) {
+                if (tie(%parmhash,'GDBM_File',$fn.'_parms.db',&GDBM_WRCREAT(),0640)) {
+                    $gotstate = &build_tmp_hashes($uri,$fn,$short,\%cenv);
+                    unless ($gotstate) {
+                        &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                            'Failed to write statemap at second attempt '.$fn.' for '.$uri.'.</font>');
+                    }
+                    unless (untie(%parmhash)) {
+                        &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                            'Could not untie coursemap parmhash '.$fn.'.db for '.$uri.'.</font>');
+                    }
+                } else {
+                    &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                        'Could not tie coursemap '.$fn.'__parms.db for '.$uri.'.</font>');
+                }
+                unless (untie(%hash)) {
+                    &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                        'Could not untie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
+                }
+            } else {
+               &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+                   'Could not tie coursemap '.$fn.'.db for '.$uri.'.</font>');
+            }
+            flock(LOCKFILE,LOCK_UN);
+            $lock = 0;
+        } else {
+            &Apache::lonnet::logthis('<font color="blue">WARNING: '.
+            'Could not obtain lock to tie coursemap hash '.$fn.'.db for '.$uri.'.</font>');
+        }
+    }
+    close(LOCKFILE);
+    unless (($errtext eq '') || ($env{'request.course.uri'} =~ m{^/uploaded/})) {
+        &Apache::lonmsg::author_res_msg($env{'request.course.uri'},
+                                        $errtext);
     }
-    &Apache::lonmsg::author_res_msg($env{'request.course.uri'},$errtext);
 # ------------------------------------------------- Check for critical messages
 
     my @what=&Apache::lonnet::dump('critical',$env{'user.domain'},
@@ -742,6 +818,91 @@ sub readmap {
     return ($retfurl,$errtext);
 }
 
+sub build_tmp_hashes {
+    my ($uri,$fn,$short,$cenvref) = @_;
+    unless(ref($cenvref) eq 'HASH') {
+        return;
+    }
+    my %cenv = %{$cenvref};
+    my $gotstate = 0;
+    %hash=();
+    %parmhash=();
+    $errtext='';
+    $pc=0;
+    &clear_mapalias_count();
+    &processversionfile(%cenv);
+    my $furi=&Apache::lonnet::clutter($uri);
+    $hash{'src_0.0'}=&versiontrack($furi);
+    $hash{'title_0.0'}=&Apache::lonnet::metadata($uri,'title');
+    $hash{'ids_'.$furi}='0.0';
+    $hash{'is_map_0.0'}=1;
+    &loadmap($uri,'0.0');
+    if (defined($hash{'map_start_'.$uri})) {
+        &Apache::lonnet::appenv({"request.course.id"  => $short,
+                                 "request.course.fn"  => $fn,
+                                 "request.course.uri" => $uri});
+        $env{'request.course.id'}=$short;
+        &traceroute('0',$hash{'map_start_'.$uri},'&');
+        &accinit($uri,$short,$fn);
+        &hiddenurls();
+    }
+    $errtext .= &get_mapalias_errors();
+# ------------------------------------------------------- Put versions into src
+    foreach my $key (keys(%hash)) {
+        if ($key=~/^src_/) {
+            $hash{$key}=&putinversion($hash{$key});
+        } elsif ($key =~ /^(map_(?:start|finish|pc)_)(.*)/) {
+            my ($type, $url) = ($1,$2);
+            my $value = $hash{$key};
+            $hash{$type.&putinversion($url)}=$value;
+        }
+    }
+# ---------------------------------------------------------------- Encrypt URLs
+    foreach my $id (keys(%encurl)) {
+#           $hash{'src_'.$id}=&Apache::lonenc::encrypted($hash{'src_'.$id});
+        $hash{'encrypted_'.$id}=1;
+    }
+# ----------------------------------------------- Close hashes to finally store
+# --------------------------------- Routine must pass this point, no early outs
+    $hash{'first_rid'}=$retfrid;
+    my ($mapid,$resid)=split(/\./,$retfrid);
+    $hash{'first_mapurl'}=$hash{'map_id_'.$mapid};
+    my $symb=&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},$resid,$hash{'src_'.$retfrid});
+    $retfurl=&add_get_param($hash{'src_'.$retfrid},{ 'symb' => $symb });
+    if ($hash{'encrypted_'.$retfrid}) {
+        $retfurl=&Apache::lonenc::encrypted($retfurl,(&Apache::lonnet::allowed('adv') ne 'F'));
+    }
+    $hash{'first_url'}=$retfurl;
+# ---------------------------------------------------- Store away initial state
+    {
+        my $cfh;
+        if (open($cfh,">$fn.state")) {
+            print $cfh join("\n",@cond);
+            $gotstate = 1;
+        } else {
+            &Apache::lonnet::logthis("<font color=blue>WARNING: ".
+                                     "Could not write statemap $fn for $uri.</font>");
+        }
+    }
+    return $gotstate;
+}
+
+sub unlink_tmpfiles {
+    my ($fn) = @_;
+    if ($fn =~ m{^\Q$Apache::lonnet::perlvar{'lonUsersDir'}\E/tmp/}) {
+        my @files = qw (.db _symb.db .state _parms.db);
+        foreach my $file (@files) {
+            if (-e $fn.$file) {
+                unless (unlink($fn.$file)) {
+                    &Apache::lonnet::logthis("<font color=blue>WARNING: ".
+                                 "Could not unlink ".$fn.$file."</font>");
+                }
+            }
+        }
+    }
+    return;
+}
+
 # ------------------------------------------------------- Evaluate state string
 
 sub evalstate {
@@ -778,10 +939,47 @@ sub evalstate {
 	    }
 	}
     }
-    &Apache::lonnet::appenv('user.state.'.$env{'request.course.id'} => $state);
+    &Apache::lonnet::appenv({'user.state.'.$env{'request.course.id'} => $state});
     return $state;
 }
 
+{
+    my %mapalias_cache;
+    sub count_mapalias {
+	my ($value,$resid) = @_;
+ 	push(@{ $mapalias_cache{$value} }, $resid);
+    }
+
+    sub get_mapalias_errors {
+	my $error_text;
+	foreach my $mapalias (sort(keys(%mapalias_cache))) {
+	    next if (scalar(@{ $mapalias_cache{$mapalias} } ) == 1);
+	    my $count;
+	    my $which =
+		join('</li><li>', 
+		     map {
+			 my $id = $_;
+			 if (exists($hash{'src_'.$id})) {
+			     $count++;
+			 }
+			 my ($mapid) = split(/\./,$id);
+                         &mt('Resource "[_1]" <br /> in Map "[_2]"',
+			     $hash{'title_'.$id},
+			     $hash{'title_'.$hash{'ids_'.$hash{'map_id_'.$mapid}}});
+		     } (@{ $mapalias_cache{$mapalias} }));
+	    next if ($count < 2);
+	    $error_text .= '<div class="LC_error">'.
+		&mt('Error: Found the mapalias "[_1]" defined multiple times.',
+		    $mapalias).
+		'</div><ul><li>'.$which.'</li></ul>';
+	}
+	&clear_mapalias_count();
+	return $error_text;
+    }
+    sub clear_mapalias_count {
+	undef(%mapalias_cache);
+    }
+}
 1;
 __END__