--- loncom/homework/cleanxml/post_xml.pm	2016/01/08 20:32:42	1.6
+++ loncom/homework/cleanxml/post_xml.pm	2016/01/14 16:28:06	1.7
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Third step to clean a file.
 #
-# $Id: post_xml.pm,v 1.6 2016/01/08 20:32:42 damieng Exp $
+# $Id: post_xml.pm,v 1.7 2016/01/14 16:28:06 damieng Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -41,6 +41,8 @@ use Cwd 'abs_path';
 use XML::LibXML;
 use HTML::TokeParser; # used to parse sty files
 use Tie::IxHash; # for ordered hashes
+use tth;
+use Apache::html_to_xml;
 
 no warnings 'recursion'; # yes, fix_paragraph is using heavy recursion, I know
 
@@ -552,11 +554,11 @@ sub replace_m {
 # Returns the HTML equivalent of LaTeX input, using tth
 sub tth {
   my ($text) = @_;
-  my ($fh, $tmp_path) = tempfile();
-  binmode($fh, ':utf8');
-  print $fh $text;
-  close $fh;
-  my $output = `tth -r -w2 -u -y0 < $tmp_path 2>/dev/null`;
+  my $output = &tth::tth($text);
+  my $errorstring = &tth::ttherror();
+  if ($errorstring) {
+    die $errorstring;
+  }
   # hopefully the temp file will not be removed before this point (otherwise we should use unlink_on_destroy 0)
   $output =~ s/^\s*|\s*$//;
   $output =~ s/<div class="p"><!----><\/div>/<br\/>/; # why is tth using such ugly markup for \newline ?
@@ -567,7 +569,7 @@ sub tth {
 sub html_to_dom {
   my ($text) = @_;
   $text = '<root>'.$text.'</root>';
-  my $textref = html_to_xml::html_to_xml(\$text);
+  my $textref = Apache::html_to_xml::html_to_xml(\$text);
   utf8::upgrade($$textref); # otherwise the XML parser fails when the HTML parser turns &nbsp; into a character
   my $dom_doc = XML::LibXML->load_xml(string => $textref);
   my $root = $dom_doc->documentElement;