Remove remove old result dir in direct g2html output

Author: sim642

src/framework/xsltResultOutput.ml

@@ -309,6 +309,7 @@ struct
 
   let output table live gtable gtfxml (module FileCfg: MyCFG.FileCfg) =
     let result_dir = Fpath.(v "result") in
+    GobSys.rmdir_recursive_if_exists result_dir;
     GobSys.mkdir_or_exists result_dir;
     let file = FileCfg.file in
     let file2funs = SH.create 100 in

src/util/std/gobSys.ml

@@ -25,7 +25,8 @@ let rmdir_if_empty dirname =
   with Unix.Unix_error (Unix.ENOTEMPTY, _, _) ->
     ()
 
-(** Remove directory and its content, as "rm -rf" would do. *)
+(** Remove directory and its content, as "rm -rf" would do.
+    @raise Sys_error if [path] doesn't exist. *)
 let rmdir_recursive path =
   let rec f path =
     let path_str = Fpath.to_string path in
@@ -38,6 +39,12 @@ let rmdir_recursive path =
   in
   f path
 
+let rmdir_recursive_if_exists path =
+  try
+    rmdir_recursive path
+  with Sys_error _ ->
+    ()
+
 
 let exe_dir = Fpath.(parent (v Sys.executable_name))