src/Pure/Thy/present.ML

     (fn {name, html_prefix, doc_prefix, graph_path, all_graph_path, path, ...} =>
   let
     val {theories, tex_index, html_index, graph, all_graph} = ! browser_info;
 
     fun finish_node (a, {tex_source, html_source = _, html}) =
-     (apsome (fn p => Buffer.write_nonempty (Path.append p (tex_path a)) tex_source) doc_prefix;
+     (apsome (fn p => Buffer.write (Path.append p (tex_path a)) tex_source) doc_prefix;
       Buffer.write (Path.append html_prefix (html_path a)) (Buffer.add HTML.end_theory html));
   in
     seq finish_node (Symtab.dest theories);
     Buffer.write (Path.append html_prefix pre_index_path) html_index;
     apsome (fn p => Buffer.write (Path.append p doc_index_path) tex_index) doc_prefix;