--- loncom/homework/lonhomework.pm	2002/01/17 12:23:31	1.69
+++ loncom/homework/lonhomework.pm	2002/01/30 17:39:13	1.70
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # The LON-CAPA Homework handler
 #
-# $Id: lonhomework.pm,v 1.69 2002/01/17 12:23:31 harris41 Exp $
+# $Id: lonhomework.pm,v 1.70 2002/01/30 17:39:13 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -218,32 +218,37 @@ sub setupheader {
 
 sub handle_save_or_undo {
   my ($request,$problem,$result) = @_;
-  my $fileout = &Apache::lonnet::filelocation("",$request->uri);
-  my $filesave=$fileout.".bak";
+  my $file    = &Apache::lonnet::filelocation("",$request->uri);
+  my $filebak =$file.".bak";
+  my $filetmp =$file.".tmp";
   my $error=0;
 
   if ($ENV{'form.Undo'} eq 'undo') {
-    if (copy($filesave,$fileout)) {
-      $request->print("<b>Undid changes, Copied $filesave to $fileout<br /></b>");
+    my $error=0;
+    if (!copy($file,$filetmp)) { $error=1; }
+    if ((!$error) && (!copy($filebak,$file))) { $error=1; }
+    if ((!$error) && (!move($filetmp,$filebak))) { $error=1; }
+    if (!$error) {
+      $request->print("<p><b>Undid changes, Switched $filebak and $file</b></p>");
     } else {
-      $request->print("<font color=\"red\" size=\"+1\"><b>Unable to undo, unable to copy $filesave to $fileout<br /></b></font>");
+      $request->print("<p><font color=\"red\" size=\"+1\"><b>Unable to undo, unable to switch $filebak and $file</b></font></p>");
       $error=1;
     }
   } else {
-    my $fs=Apache::File->new(">$filesave");
+    my $fs=Apache::File->new(">$filebak");
     if (defined($fs)) {
       print $fs $$problem;
-      $request->print("<b>Making Backup to $filesave</b><br />");
+      $request->print("<b>Making Backup to $filebak</b><br />");
     } else {
-      $request->print("<font color=\"red\" size=\"+1\"><b>Unable to make backup $filesave</b></font>");
+      $request->print("<font color=\"red\" size=\"+1\"><b>Unable to make backup $filebak</b></font>");
       $error=2;
     }
-    my $fh=Apache::File->new(">$fileout");
+    my $fh=Apache::File->new(">$file");
     if (defined($fh)) {
       print $fh $$result;
-      $request->print("<b>Saving Modifications to $fileout</b><br />");
+      $request->print("<b>Saving Modifications to $file</b><br />");
     } else {
-      $request->print("<font color=\"red\" size=\"+1\"><b>Unable to write to $fileout</b></font>");
+      $request->print("<font color=\"red\" size=\"+1\"><b>Unable to write to $file</b></font>");
       $error|=4;
     }
   }
@@ -286,6 +291,7 @@ sub renderpage {
   my ($request,$file) = @_;
 
   my (@targets) = &get_target();
+  &Apache::lonxml::debug("Running targets ".join(':',@targets));
   foreach my $target (@targets) {
     #my $t0 = [&gettimeofday()];
     my $problem=&Apache::lonnet::getfile($file);
@@ -314,6 +320,7 @@ sub renderpage {
       &Apache::lonxml::error("<b>Unable to find <i>default_homework.lcpm</i></b>");
       $default='';
     }
+    &Apache::lonxml::debug("Should be parsing now");
     $result = &Apache::lonxml::xmlparse($target, $problem,
 			$default.&setup_vars($target),%mystyle);