Index: subversion/bindings/swig/ruby/svn/wc.rb
===================================================================
--- subversion/bindings/swig/ruby/svn/wc.rb	(revision 25251)
+++ subversion/bindings/swig/ruby/svn/wc.rb	(working copy)
@@ -297,13 +297,15 @@
 
       def update_editor(target_revision, target, use_commit_times=true,
                         depth=nil, allow_unver_obstruction=false, diff3_cmd=nil,
-                        notify_func=nil, cancel_func=nil, traversal_info=nil)
+                        notify_func=nil, cancel_func=nil, traversal_info=nil,
+                        preserved_exts=nil)
+        preserved_exts ||= []
         traversal_info ||= _traversal_info
         results = Wc.get_update_editor3(target_revision, self, target,
                                         use_commit_times, depth,
                                         allow_unver_obstruction,
                                         notify_func, cancel_func, diff3_cmd,
-                                        traversal_info)
+                                        preserved_exts, traversal_info)
         target_revision_address, editor, editor_baton = results
         editor.__send__(:target_revision_address=, target_revision_address)
         editor.baton = editor_baton
@@ -313,13 +315,16 @@
       def switch_editor(target_revision, target, switch_url,
                         use_commit_times=true, depth=nil,
                         allow_unver_obstruction=false, diff3_cmd=nil,
-                        notify_func=nil, cancel_func=nil, traversal_info=nil)
+                        notify_func=nil, cancel_func=nil, traversal_info=nil,
+                        preserved_exts=nil)
+        preserved_exts ||= []
         traversal_info ||= _traversal_info
         results = Wc.get_switch_editor3(target_revision, self, target,
                                         switch_url, use_commit_times, depth,
                                         allow_unver_obstruction,
                                         notify_func, cancel_func,
-                                        diff3_cmd, traversal_info)
+                                        diff3_cmd, preserved_exts,
+                                        traversal_info)
         target_revision_address, editor, editor_baton = results
         editor.__send__(:target_revision_address=, target_revision_address)
         editor.baton = editor_baton
Index: subversion/bindings/swig/include/svn_containers.swg
===================================================================
--- subversion/bindings/swig/include/svn_containers.swg	(revision 25251)
+++ subversion/bindings/swig/include/svn_containers.swg	(working copy)
@@ -396,12 +396,18 @@
 
 /* svn_delta_path_driver() mutates its 'paths' argument (by sorting it),
    despite the fact that it is notionally an input parameter - hence, the
-   lack of 'const' in that one case. */
+   lack of 'const' in that one case. 
+   
+   svn_wc_get_update_editor3() and svn_wc_get_switch_editor3() aren't changing 
+   their 'preserved_exts' argument, but it is forwarded to 
+   svn_cstring_match_glob_list which also doesn't modify it, but does not have 
+   const in its prototype.  */
 %apply const apr_array_header_t *STRINGLIST {
   const apr_array_header_t *args,
   const apr_array_header_t *diff_options,
   apr_array_header_t *paths,
-  const apr_array_header_t *targets
+  const apr_array_header_t *targets,
+  apr_array_header_t *preserved_exts
 };
 
 /* -----------------------------------------------------------------------