Make the user_err header an optional parameter.

Suggested by @ppedrot

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/cErrors.ml b/lib/cErrors.ml
index 830a9e3ce..38ed3f5ba 100644
--- a/lib/cErrors.ml
+++ b/lib/cErrors.ml
@@ -33,12 +33,12 @@ let is_anomaly = function
 | Anomaly _ -> true
 | _ -> false
 
-exception UserError of string * std_ppcmds (* User errors *)
+exception UserError of string option * std_ppcmds (* User errors *)
 
 let todo s = prerr_string ("TODO: "^s^"\n")
 
-let user_err    ?loc s strm = Loc.raise ?loc (UserError (s,strm))
-let error            string = user_err "_" (str string)
+let user_err ?loc ?hdr strm = Loc.raise ?loc (UserError (hdr, strm))
+let error            string = user_err (str string)
 
 let invalid_arg ?loc s   = Loc.raise ?loc (Invalid_argument s)
 
@@ -112,7 +112,7 @@ let iprint_no_report (e, info) =
 
 let _ = register_handler begin function
   | UserError(s, pps) ->
-    hov 0 (str "Error: " ++ where (Some s) ++ pps)
+    hov 0 (str "Error: " ++ where s ++ pps)
   | _ -> raise Unhandled
 end