X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2FmatitaEngine.ml;h=144250fb9b55e634312523693f15f1c309d8add5;hb=c8718cc46ab9aaca047366dfefe72bc7c9402e5a;hp=5d16763fc36ad6db0b685937e47e53fdc11e2c5b;hpb=98f0fac6d03367be776303e7ba353b75878aaa40;p=helm.git

diff --git a/matita/matita/matitaEngine.ml b/matita/matita/matitaEngine.ml
index 5d16763fc..144250fb9 100644
--- a/matita/matita/matitaEngine.ml
+++ b/matita/matita/matitaEngine.ml
@@ -71,15 +71,17 @@ let cut prefix s =
   String.sub s lenp (lens-lenp)
 ;;
 
-let print_string =
+let print_string = 
  let indent = ref 0 in
  let print_string ~right_justify s =
   let ss =
    match right_justify with
       None -> ""
     | Some (ss,len_ss) ->
-       String.make (80 - !indent - len_ss - String.length s) ' ' ^ ss
+       let i = 80 - !indent - len_ss - String.length s in
+       if i > 0 then String.make i ' ' ^ ss else ss
   in
+   assert (!indent >=0);
    print_string (String.make !indent ' ' ^ s ^ ss) in
  fun enter ?right_justify s ->
   if enter then (print_string ~right_justify s; incr indent) else (decr indent; print_string ~right_justify s)