Fix a bug (in LucFGen) where the exception Invalid_argument("Random.int") was...

Fix a bug (in LucFGen) where the exception Invalid_argument("Random.int") was raised on some Lutin programs.

It was occuring when all outgoing transitions were labelled by the
null weigth.

source/common/control.ml

@@ -87,7 +87,10 @@ let (set_between : string -> int -> int -> int -> state -> state) =
 (* exported *)
 let (draw_between : string -> int -> int -> state -> state) =
   fun id min max st ->
-    let draw = min + (Random.int (max - min + 1)) in
+    let draw =
+      assert(max - min + 1 > 0);
+      min + (Random.int (max - min + 1)) 
+    in
       StringMap.add id (draw, (Some(min, max))) st
 
 (* exported *)

source/common/lucFGen.ml

@@ -130,11 +130,11 @@ and
 	        | _,_ -> And(f,facc) 
             in
             let ctx_msg = Prog.ctrl_state_to_string_long state.d.ctrl_state in
-Utils.time_C "is_sat";
-            let sat = (Solver.is_satisfiable input state.d.memory state.d.verbose ctx_msg facc' "") in
-Utils.time_R "is_sat";
-	      if  sat then (cont', facc', n)
-              else choose_one_formula_atomic input state facc cont'
+              Utils.time_C "is_sat";
+              let sat = (Solver.is_satisfiable input state.d.memory state.d.verbose ctx_msg facc' "") in
+                Utils.time_R "is_sat";
+	        if  sat then (cont', facc', n)
+                else choose_one_formula_atomic input state facc cont'
 
 
 and (wt_to_cont : Var.env_in -> Prog.state -> wt -> wt_cont -> wt_cont) =
@@ -153,31 +153,32 @@ and (wt_to_cont : Var.env_in -> Prog.state -> wt -> wt_cont -> wt_cont) =
 		   | [] -> 
 		       let get_weigth dw = 
 			 match dw with
-			   | V i -> i
+			   | V i -> if i < 0 then 0 else i (* a negative weight means null weigth *)
 			   | Infin -> assert false
 		       in
  		       let w_sum =
 			 List.fold_left (fun acc (dw,_) -> acc+(get_weigth dw)) 0 l2
 		       in
-		       let j = 1 + Random.int w_sum in
-		       let rec get_jth_trans j list acc =
-			 match list with
-			     [] -> assert false
-			   | (dw,nt)::tail ->
-			       let newj = j - (get_weigth dw) in
-				 if (newj < 1) then 
-				   nt, (rev_append acc tail) 
-				 else 
-				   get_jth_trans newj tail ((dw,nt)::acc)	
-		       in
-		       let (nt,l2') = get_jth_trans j l2 [] in
-		       let tbl' = Util.StringMap.add n (Children l2') tbl in
-		       let tbl'' = Util.StringMap.remove n tbl in (* to optimize mem *)
-		       let cont' =  WCont(fun () ->
-				            call_wt_cont (wt_to_cont input state (tbl', n) cont)
-					 )
-		       in
-			 wt_to_cont input state (tbl'', nt) cont'
+                         if w_sum = 0 then cont else
+		           let j = 1 + Random.int w_sum in
+		           let rec get_jth_trans j list acc =
+			     match list with
+			         [] -> assert false
+			       | (dw,nt)::tail ->
+			           let newj = j - (get_weigth dw) in
+				     if (newj < 1) then 
+				       nt, (rev_append acc tail) 
+				     else 
+				       get_jth_trans newj tail ((dw,nt)::acc)	
+		           in
+		           let (nt,l2') = get_jth_trans j l2 [] in
+		           let tbl' = Util.StringMap.add n (Children l2') tbl in
+		           let tbl'' = Util.StringMap.remove n tbl in (* to optimize mem *)
+		           let cont' =  WCont(fun () ->
+				                call_wt_cont (wt_to_cont input state (tbl', n) cont)
+					     )
+		           in
+			     wt_to_cont input state (tbl'', nt) cont'
 
 		   | [(_,nt)] -> 
 		       let tbl' = Util.StringMap.add n (Children l2) tbl in