--- loncom/lonnet/perl/lonnet.pm	2012/12/03 14:47:37	1.1205
+++ loncom/lonnet/perl/lonnet.pm	2013/02/02 03:29:33	1.1211
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # TCP networking package
 #
-# $Id: lonnet.pm,v 1.1205 2012/12/03 14:47:37 raeburn Exp $
+# $Id: lonnet.pm,v 1.1211 2013/02/02 03:29:33 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -2716,10 +2716,14 @@ sub can_edit_resource {
                 return;
             }
         } else {
+            if ($resurl =~ m{^/?adm/viewclasslist$}) {
+                unless (&Apache::lonnet::allowed('opa',$env{'request.course.id'})) {
+                    return;
+                }
+            } elsif (!$crsedit) {
 #
 # No edit allowed where CC has switched to student role.
 #
-            unless ($crsedit) {
                 return;
             }
         }
@@ -2766,6 +2770,14 @@ sub can_edit_resource {
                         $forceedit = 1;
                     }
                     $cfile = $resurl;
+                } elsif ($resurl =~ m{^/?adm/viewclasslist$}) {
+                    $incourse = 1;
+                    if ($env{'form.forceedit'}) {
+                        $forceview = 1;
+                    } else {
+                        $forceedit = 1;
+                    }
+                    $cfile = ($resurl =~ m{^/} ? $resurl : "/$resurl");
                 }
             } elsif ($resurl eq '/res/lib/templates/simpleproblem.problem/smpedit') {
                 my $template = '/res/lib/templates/simpleproblem.problem';
@@ -2798,7 +2810,7 @@ sub can_edit_resource {
         }
         if ($uploaded || $incourse) {
             $home=&homeserver($cnum,$cdom);
-        } else {
+        } elsif ($file !~ m{/$}) {
             $file=~s{^(priv/$match_domain/$match_username)}{/$1};
             $file=~s{^($match_domain/$match_username)}{/priv/$1};
             # Check that the user has permission to edit this resource
@@ -6881,7 +6893,7 @@ sub constructaccess {
     if (($allowed eq 'F') || ($allowed eq 'U')) {
 # Grant temporary access
         my $then=$env{'user.login.time'};
-        my $update==$env{'user.update.time'};
+        my $update=$env{'user.update.time'};
         if (!$update) { $update = $then; }
         my $refresh=$env{'user.refresh.time'};
         if (!$refresh) { $refresh = $update; }
@@ -10622,14 +10634,14 @@ sub deversion {
 
 sub symbread {
     my ($thisfn,$donotrecurse)=@_;
-    my $cache_str='request.symbread.cached.'.$thisfn;
-    if (defined($env{$cache_str})) {
-        if (($thisfn) || ($env{$cache_str} ne '')) {
+    my $cache_str;
+    if ($thisfn ne '') {
+        $cache_str='request.symbread.cached.'.$thisfn;
+        if ($env{$cache_str} ne '') {
             return $env{$cache_str};
         }
-    }
+    } else {
 # no filename provided? try from environment
-    unless ($thisfn) {
         if ($env{'request.symb'}) {
 	    return $env{$cache_str}=&symbclean($env{'request.symb'});
 	}
@@ -11544,12 +11556,12 @@ sub goodbye {
 }
 
 sub get_dns {
-    my ($url,$func,$ignore_cache) = @_;
+    my ($url,$func,$ignore_cache,$nocache,$hashref) = @_;
     if (!$ignore_cache) {
 	my ($content,$cached)=
 	    &Apache::lonnet::is_cached_new('dns',$url);
 	if ($cached) {
-	    &$func($content);
+	    &$func($content,$hashref);
 	    return;
 	}
     }
@@ -11574,8 +11586,10 @@ sub get_dns {
         delete($alldns{$dns});
 	next if ($response->is_error());
 	my @content = split("\n",$response->content);
-	&Apache::lonnet::do_cache_new('dns',$url,\@content,30*24*60*60);
-	&$func(\@content);
+	unless ($nocache) {
+	    &Apache::lonnet::do_cache_new('dns',$url,\@content,30*24*60*60);
+	}
+	&$func(\@content,$hashref);
 	return;
     }
     close($config);
@@ -11583,9 +11597,62 @@ sub get_dns {
     &logthis("unable to contact DNS defaulting to on disk file dns_$which.tab\n");
     open($config,"<$perlvar{'lonTabDir'}/dns_$which.tab");
     my @content = <$config>;
-    &$func(\@content);
+    &$func(\@content,$hashref);
     return;
 }
+
+# ------------------------------------------------------Get DNS checksums file
+sub parse_dns_checksums_tab {
+    my ($lines,$hashref) = @_;
+    my $machine_dom = &Apache::lonnet::host_domain($perlvar{'lonHostID'});
+    my $loncaparev = &get_server_loncaparev($machine_dom);
+    my ($release,$timestamp) = split(/\-/,$loncaparev);
+    my (%chksum,%revnum);
+    if (ref($lines) eq 'ARRAY') {
+        chomp(@{$lines});
+        my $versions = shift(@{$lines});
+        my %supported;
+        if ($versions =~ /^VERSIONS\:([\w\.\,]+)$/) {
+            my $releaseslist = $1;
+            if ($releaseslist =~ /,/) {
+                map { $supported{$_} = 1; } split(/,/,$releaseslist);
+            } elsif ($releaseslist) {
+                $supported{$releaseslist} = 1;
+            }
+        }
+        if ($supported{$release}) {  
+            my $matchthis = 0;
+            foreach my $line (@{$lines}) {
+                if ($line =~ /^(\d[\w\.]+)$/) {
+                    if ($matchthis) {
+                        last;
+                    } elsif ($1 eq $release) {
+                        $matchthis = 1;
+                    }
+                } elsif ($matchthis) {
+                    my ($file,$version,$shasum) = split(/,/,$line);
+                    $chksum{$file} = $shasum;
+                    $revnum{$file} = $version;
+                }
+            }
+            if (ref($hashref) eq 'HASH') {
+                %{$hashref} = (
+                                sums     => \%chksum,
+                                versions => \%revnum,
+                              );
+            }
+        }
+    }
+    return;
+}
+
+sub fetch_dns_checksums {
+    my %checksums; 
+    &get_dns('/adm/dns/checksums',\&parse_dns_checksums_tab,1,1,
+             \%checksums);
+    return \%checksums;
+}
+
 # ------------------------------------------------------------ Read domain file
 {
     my $loaded;