--- loncom/xml/lonxml.pm	2006/01/13 10:33:25	1.395
+++ loncom/xml/lonxml.pm	2006/03/09 00:39:28	1.400
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # XML Parser Module 
 #
-# $Id: lonxml.pm,v 1.395 2006/01/13 10:33:25 albertel Exp $
+# $Id: lonxml.pm,v 1.400 2006/03/09 00:39:28 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -149,6 +149,19 @@ $Apache::lonxml::post_evaluate=1;
 #a header message to emit in the case of any generated warning or errors
 $Apache::lonxml::warnings_error_header='';
 
+#  Control whether or not LaTeX symbols should be substituted for their
+#  \ style equivalents...this may be turned off e.g. in an verbatim
+#  environment.
+
+$Apache::lonxml::substitute_LaTeX_symbols = 1; # Starts out on.
+
+sub enable_LaTeX_substitutions {
+    $Apache::lonxml::substitute_LaTeX_symbols = 1;
+}
+sub disable_LaTeX_substitutions {
+    $Apache::lonxml::substitute_LaTeX_symbols = 0;
+}
+
 sub xmlbegin {
     my ($style)=@_;
     my $output='';
@@ -382,6 +395,13 @@ sub xmlparse {
 
 sub latex_special_symbols {
     my ($string,$where)=@_;
+    #
+    #  If e.g. in verbatim mode, then don't substitute.
+    #  but return original string.
+    #
+    if (!($Apache::lonxml::substitute_LaTeX_symbols)) {
+	return $string;
+    }
     if ($where eq 'header') {
 	$string =~ s/(\\|_|\^)/ /g;
 	$string =~ s/(\$|%|\{|\})/\\$1/g;
@@ -629,6 +649,7 @@ sub setup_globals {
   @Apache::lonxml::ssi_info=();
   $Apache::lonxml::post_evaluate=1;
   $Apache::lonxml::warnings_error_header='';
+  $Apache::lonxml::substitute_LaTeX_symbols = 1;
   if ($target eq 'meta') {
     $Apache::lonxml::redirection = 0;
     $Apache::lonxml::metamode = 1;
@@ -950,6 +971,16 @@ sub decreasedepth {
 #print "<br />e $Apache::lonxml::depth : $Apache::lonxml::olddepth : $token->[1] : $curdepth\n";
 }
 
+sub get_id {
+    my ($parstack,$safeeval)=@_;
+    my $id= &Apache::lonxml::get_param('id',$parstack,$safeeval);
+    if ($env{'request.state'} eq 'construct' && $id =~ /(\.|_)/) {
+	&error(&mt("IDs are not allowed to contain &quot;<tt>_</tt>&quot; or &quot;<tt>.</tt>&quot;"));
+    }
+    if ($id =~ /^\s*$/) { $id = $Apache::lonxml::curdepth; }
+    return $id;
+}
+
 sub get_all_text_unbalanced {
 #there is a copy of this in lonpublisher.pm
     my($tag,$pars)= @_;
@@ -1010,6 +1041,27 @@ sub store_counter {
     return '';
 }
 
+{
+    my $state;
+    sub clear_problem_counter {
+	undef($state);
+	&Apache::lonnet::delenv('form.counter');
+	&Apache::lonxml::init_counter();
+	&Apache::lonxml::store_counter();
+    }
+
+    sub remember_problem_counter {
+	&Apache::lonnet::transfer_profile_to_env();
+	$state = $env{'form.counter'};
+    }
+
+    sub restore_problem_counter {
+	if (defined($state)) {
+	    &Apache::lonnet::appenv(('form.counter' => $state));
+	}
+    }
+}
+
 sub get_all_text {
     my($tag,$pars,$style)= @_;
     my $gotfullstack=1;