2 files changed, 15 insertions, 7 deletions
diff --git a/otherlibs/labltk/browser/editor.ml b/otherlibs/labltk/browser/editor.ml
index ceadef8f7..a8cca85ac 100644
--- a/otherlibs/labltk/browser/editor.ml
+++ b/otherlibs/labltk/browser/editor.ml
@@ -402,12 +402,14 @@ class editor ~top ~menus = object (self)
     if txt.name <> name then current_dir <- Filename.dirname name;
     try
       if Sys.file_exists name then
-        if txt.name = name then
-          Sys.rename name (name ^ "~")
-        else begin match
-          Jg_message.ask ~master:top ~title:"Save"
-            ("File `" ^ name ^ "' exists. Overwrite it?")
-        with `yes -> () | `no | `cancel -> raise Exit
+        if txt.name = name then begin
+          let backup = name ^ "~" in
+          if Sys.file_exists backup then Sys.remove backup;
+          try Sys.rename name backup with Sys_error _ -> ()
+        end else begin
+          match Jg_message.ask ~master:top ~title:"Save"
+              ("File `" ^ name ^ "' exists. Overwrite it?")
+          with `yes -> () | `no | `cancel -> raise Exit
         end;
       let file = open_out name in
       let text = Text.get txt.tw ~start:tstart ~stop:(tposend 1) in
diff --git a/otherlibs/labltk/browser/main.ml b/otherlibs/labltk/browser/main.ml
index 427395d34..935203401 100644
--- a/otherlibs/labltk/browser/main.ml
+++ b/otherlibs/labltk/browser/main.ml
@@ -62,6 +62,11 @@ let _ =
   Searchpos.view_defined_ref := (fun s ~env -> Viewer.view_defined s ~env);
   Searchpos.editor_ref := Editor.f;
 
+  let is_win32 = Sys.os_type = "Win32" in
+  if is_win32 then
+    Format.pp_set_formatter_output_functions Format.err_formatter
+      (fun _ _ _ -> ()) (fun _ -> ());
+
   let top = openTk ~clas:"OCamlBrowser" () in
   Jg_config.init ();
 
@@ -74,6 +79,7 @@ let _ =
 
   while true do
     try
-      Printexc.print mainLoop ()
+      if is_win32 then mainLoop ()
+      else Printexc.print mainLoop ()
     with Protocol.TkError _ -> ()
   done