--- loncom/interface/londocs.pm	2008/12/13 23:32:01	1.314.2.1
+++ loncom/interface/londocs.pm	2008/12/21 16:15:39	1.314.2.4
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Documents
 #
-# $Id: londocs.pm,v 1.314.2.1 2008/12/13 23:32:01 raeburn Exp $
+# $Id: londocs.pm,v 1.314.2.4 2008/12/21 16:15:39 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -280,6 +280,15 @@ sub exportcourse {
                                                $env{'course.'.$env{'request.course.id'}.'.domain'}, $env{'course.'.$env{'request.course.id'}.'.num'});
     my $numdisc = keys %discussiontime;
     my $navmap = Apache::lonnavmaps::navmap->new();
+    if (!defined($navmap)) {
+        $r->print(&Apache::loncommon::start_page('Export '.lc($type).' to IMS content package').
+                  '<h2>IMS Export Failed</h2>'.
+                  '<div class="LC_error">'.
+                  &mt('Unable to retrieve information about course contents').
+                  '</div><a href="/adm/coursedocs">'.&mt('Return to Course Editor').'</a>');
+        &Apache::lonnet::logthis('IMS export failed - could not create navmap object in '.lc($type).':'.$env{'request.course.id'});
+        return;
+    }
     my $it=$navmap->getIterator(undef,undef,undef,1,undef,undef);
     my $curRes;
     my $outcome;
@@ -471,8 +480,7 @@ function containerCheck(item) {
 	$r->print($display.'</table>'.
                   '<p><input type="hidden" name="finishexport" value="1">'.
                   '<input type="submit" name="exportcourse" value="'.
-                  &mt('Export '.$type.' DOCS').'" /></p></form>'.
-		  &Apache::loncommon::end_page());
+                  &mt('Export '.$type.' DOCS').'" /></p></form>');
     }
 }
 
@@ -1279,9 +1287,33 @@ sub do_paste_from_buffer {
 # Maps need to be copied first
     if (($url=~/\.(page|sequence)$/) && ($url=~/^\/uploaded\//)) {
 	$title=&mt('Copy of').' '.$title;
-	my $newid=$$.time;
-	$url=~/^(.+)\.(\w+)$/;
-	my $newurl=$1.$newid.'.'.$2;
+        my $newid=$$.int(rand(100)).time;
+	my ($oldid,$ext) = ($url=~/^(.+)\.(\w+)$/);
+        if ($oldid =~ m{^(/uploaded/\Q$coursedom\E/\Q$coursenum\E/)(\D+)(\d+)$}) {
+            my $path = $1;
+            my $prefix = $2;
+            my $ancestor = $3;
+            if (length($ancestor) > 10) {
+                $ancestor = substr($ancestor,-10,10);
+            }
+            $oldid = $path.$prefix.$ancestor;
+        }
+        my $counter = 0;
+        my $newurl=$oldid.$newid.'.'.$ext;
+        my $is_unique = &uniqueness_check($newurl);
+        while (!$is_unique && $counter < 100) {
+            $counter ++;
+            $newid ++;
+            $newurl = $oldid.$newid;
+            $is_unique = &uniqueness_check($newurl);
+        }
+        if (!$is_unique) {
+            if ($url=~/\.page$/) {
+                return &mt('Paste failed: an error occurred creating a unique URL for the composite page');
+            } else {
+                return &mt('Paste failed: an error occurred creating a unique URL for the folder');
+            }
+        }
 	my $storefn=$newurl;
 	$storefn=~s{^/\w+/$match_domain/$match_username/}{};
 	&Apache::lonclonecourse::writefile($env{'request.course.id'},$storefn,
@@ -1330,6 +1362,20 @@ sub do_paste_from_buffer {
 # Store the result
 }
 
+sub uniqueness_check {
+    my ($newurl) = @_;
+    my $unique = 1;
+    foreach my $res (@LONCAPA::map::order) {
+        my ($name,$url)=split(/\:/,$LONCAPA::map::resources[$res]);
+        $url=&LONCAPA::map::qtescape($url);
+        if ($newurl eq $url) {
+            $unique = 0;
+            last;    
+        }
+    }
+    return $unique;
+}
+
 my %parameter_type = ( 'randompick'     => 'int_pos',
 		       'hiddenresource' => 'string_yesno',
 		       'encrypturl'     => 'string_yesno',
@@ -2070,14 +2116,23 @@ sub checkonthis {
 sub list_symbs {
     my ($r) = @_;
 
+    my $type = &Apache::loncommon::course_type();
     $r->print(&Apache::loncommon::start_page('Symb List'));
     $r->print(&Apache::lonhtmlcommon::breadcrumbs('Symb List'));
     my $navmap = Apache::lonnavmaps::navmap->new();
-    $r->print("<pre>\n");
-    foreach my $res ($navmap->retrieveResources()) {
-	$r->print($res->compTitle()."\t".$res->symb()."\n");
+    if (!defined($navmap)) {
+        $r->print('<h2>'.&mt('Retrieval of List Failed').'</h2>'.
+                  '<div class="LC_error">'.
+                  &mt('Unable to retrieve information about course contents').
+                  '</div>');
+        &Apache::lonnet::logthis('Symb list failed - could not create navmap object in '.lc($type).':'.$env{'request.course.id'});
+    } else {
+        $r->print("<pre>\n");
+        foreach my $res ($navmap->retrieveResources()) {
+	    $r->print($res->compTitle()."\t".$res->symb()."\n");
+        }
+        $r->print("\n</pre>\n");
     }
-    $r->print("\n</pre>\n");
     $r->print('<a href="/adm/coursedocs">'.&mt('Return to DOCS').'</a>');
 }