--- loncom/homework/cleanxml/post_xml.pm	2016/01/14 16:28:06	1.7
+++ loncom/homework/cleanxml/post_xml.pm	2016/01/21 22:09:38	1.9
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Third step to clean a file.
 #
-# $Id: post_xml.pm,v 1.7 2016/01/14 16:28:06 damieng Exp $
+# $Id: post_xml.pm,v 1.9 2016/01/21 22:09:38 damieng Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -128,6 +128,8 @@ sub post_xml {
   
   remove_useless_notsolved($root);
   
+  fix_comments($root);
+  
   fix_paragraphs_inside($root, \@all_block);
 
   remove_empty_style($root);
@@ -1810,12 +1812,31 @@ sub remove_useless_notsolved {
   }
 }
 
+# Use <pre> for multi-line comments without elements.
+sub fix_comments {
+  my ($root) = @_;
+  my $doc = $root->ownerDocument;
+  my @comments = $root->getElementsByTagName('comment');
+  foreach my $comment (@comments) {
+    my $first = $comment->firstChild;
+    if (defined $first) {
+      if ($first->nodeType == XML_TEXT_NODE && $first->nodeValue =~ /\n/ &&
+          !defined $first->nextSibling) {
+        my $pre = $doc->createElement('pre');
+        $comment->removeChild($first);
+        $comment->appendChild($pre);
+        $pre->appendChild($first);
+      }
+    }
+  }
+}
+
 # adds a paragraph inside if needed and calls fix_paragraph for all paragraphs (including new ones)
 sub fix_paragraphs_inside {
   my ($node, $all_block) = @_;
   # blocks in which paragrahs will be added:
-  my @blocks_with_p = ('loncapa','library','problem','part','problemtype','window','block','while','postanswerdate','preduedate','solved','notsolved','languageblock','instructorcomment','togglebox','standalone','body','form');
-  my @fix_p_if_br_or_p = (@responses,'foil','item','text','label','hintgroup','hintpart','hint','web','windowlink','div','li','dd','td','th','blockquote');
+  my @blocks_with_p = ('loncapa','library','problem','part','problemtype','window','block','while','postanswerdate','preduedate','languageblock','instructorcomment','togglebox','standalone','body','form');
+  my @fix_p_if_br_or_p = (@responses,'foil','item','text','label','hintgroup','hintpart','hint','web','windowlink','div','li','dd','td','th','blockquote','solved','notsolved');
   if ((string_in_array(\@blocks_with_p, $node->nodeName) && paragraph_needed($node)) ||
       (string_in_array(\@fix_p_if_br_or_p, $node->nodeName) && paragraph_inside($node))) {
     # if non-empty, add paragraphs where needed between all br and remove br