Index: lib/TWiki/Templates.pm
===================================================================
--- lib/TWiki/Templates.pm	(revision 12220)
+++ lib/TWiki/Templates.pm	(working copy)
@@ -131,6 +131,8 @@
 
 Recursively expands any contained TMPL:P tags.
 
+#SMELL - there is no recursion detection - if you define 2 blocks in terms of each other, you kill your server :(
+
 Note that it would be trivial to add template parameters to this,
 simply by iterating over the other parameters (other than _DEFAULT, context,
 then and else) and doing a s/// in the template for that parameter value. This
@@ -207,10 +209,47 @@
 
 =cut
 
+sub saveTemplateToCache {
+    my( $this, $cacheName, $name, $skins, $web, $tmplText ) = @_;
+    $skins = '' unless (defined($skins));
+    $web = '' unless (defined($web));
+    
+    my $tmpl_cachedir = $TWiki::cfg{TemplateDir}.$cacheName;
+    mkdir($tmpl_cachedir) unless (-e $tmpl_cachedir);
+    my $filename =  TWiki::Sandbox::untaintUnchecked($tmpl_cachedir.'/'.$name.'__'.$skins.'__'.$web.'.tmpl');
+    
+    unless ( open( FILE, ">$filename" ) )  {
+        die "Can't create file $filename - $!\n";
+    }
+    print FILE $tmplText;
+    close( FILE);
+}
+sub getTemplateFromCache {
+    my( $this, $name, $skins, $web ) = @_;
+    $skins = '' unless (defined($skins));
+    $web = '' unless (defined($web));
+
+    my $tmpl_cachedir = $TWiki::cfg{TemplateDir}.'_cache';
+    mkdir($tmpl_cachedir) unless (-e $tmpl_cachedir);
+    my $filename =  TWiki::Sandbox::untaintUnchecked($tmpl_cachedir.'/'.$name.'__'.$skins.'__'.$web.'.tmpl');
+    
+    if (-e $filename) {
+        open( IN_FILE, "<$filename" ) || return;
+        local $/ = undef; # set to read to EOF
+        my $data = <IN_FILE>;
+        close( IN_FILE );
+        return $data;
+    }
+}
+
 sub readTemplate {
     my( $this, $name, $skins, $web ) = @_;
     ASSERT($this->isa( 'TWiki::Templates')) if DEBUG;
 
+#    my $cache = $this->getTemplateFromCache($name, $skins, $web);
+#    return $cache if($cache);
+#    print STDERR "template file cache miss - recreating ($name, $skins, $web)";
+        
     $this->{files} = ();
 
     # recursively read template file(s)
@@ -220,12 +259,15 @@
         $text =~ s/%TMPL\:INCLUDE{[\s\"]*(.*?)[\"\s]*}%/$this->_readTemplateFile( $1, $skins, $web )/geo;
     }
 
+    $this->saveTemplateToCache('_postinclude', $name, $skins, $web, $text);
+    
     # Kill comments, marked by %{ ... }%
     $text =~ s/%{.*?}%//sg;
 
     if( ! ( $text =~ /%TMPL\:/s ) ) {
         # no template processing
         $text =~ s|^(( {3})+)|"\t" x (length($1)/3)|geom;  # leading spaces to tabs
+        $this->saveTemplateToCache('_cache', $name, $skins, $web, $text);
         return $text;
     }
 
@@ -263,6 +305,9 @@
     $result =~ s/(%TMPL\:P{.*?}%)/$this->_expandTrivialTemplate($1)/geo;
 
     $result =~ s|^(( {3})+)|"\t" x (length($1)/3)|geom;  # leading spaces to tabs
+
+    $this->saveTemplateToCache('_cache', $name, $skins, $web, $result);
+
     return $result;
 }
 
@@ -285,7 +330,8 @@
     # if the name ends in .tmpl, then this is an explicit include from
     # the templates directory. No further searching required.
     if( $name =~ /\.tmpl$/ ) {
-        return TWiki::readFile( $TWiki::cfg{TemplateDir}.'/'.$name );
+        my $filename = $TWiki::cfg{TemplateDir}.'/'.$name;
+        return " %{ INCLUDED($filename) $name, $skins, $web }% \n".TWiki::readFile( $filename );
     }
 
     my $userdirweb = $web;
@@ -297,7 +343,7 @@
        # if the name can be parsed into $web.$name, then this is an attempt
        # to explicit include that topic. No further searching required.
        if( validateTopic($session,$store,$session->{user},$userdirname,$userdirweb )) {
-	   return retrieveTopic( $store, $userdirweb, $userdirname );
+           return " %{ INCLUDED(topic:$userdirweb, $userdirname) $name, $skins, $web }% \n".retrieveTopic( $store, $userdirweb, $userdirname );
        }
     }
     else {
@@ -344,14 +390,14 @@
 	      next if (defined($this->{files}->{$name1}));
 	      #recursion prevention.
 	      $this->{files}->{$name1} = 1;
-	      return retrieveTopic( $store, $web1, $name1 );
+	      return  " %{ INCLUDED(topic:$web1, $name1) $name, $skins, $web }% \n".retrieveTopic( $store, $web1, $name1 );
 	    }
 	  } else {
 	    if( validateFile( $file )) {
 	      next if (defined($this->{files}->{$name}));
 	      #recursion prevention.
 	      $this->{files}->{$name} = 1;
-            return TWiki::readFile( $file );
+            return " %{ INCLUDED($file) $name, $skins, $web }% \n".TWiki::readFile( $file );
 	    }
 	  }
        }
@@ -360,9 +406,9 @@
     # SMELL: should really
     #throw Error::Simple( 'Template '.$name.' was not found' );
     # instead of
-    #print STDERR "Template $name could not be found anywhere\n";
+    print STDERR "Template $name could not be found anywhere\n";
     #Is Failing Silently the best option here?
-    return '';
+    return " %{INCLUDED( not found) $name, $skins, $web}% ";
 }
 
 sub validateFile {