Minor. Debugging of copy_paste.

src/session/controller_itp.ml

@@ -763,13 +763,14 @@ let copy_detached ~copy c from_any =
       let pn_id = copy_proof_node_as_detached c.controller_session from_pn in
       let parent = get_any_parent c.controller_session from_any in
       match parent with
-      | None -> raise BadCopyDetached
+      | None -> raise (BadCopyDetached "copy_detached no parent")
       | Some parent ->
           copy ~parent (APn pn_id);
           copy_structure
             ~notification:copy c.controller_session (APn from_pn) (APn pn_id)
     end
-  | _ -> raise BadCopyDetached (* Only goal can be detached *)
+  (* Only goal can be detached *)
+  | _ -> raise (BadCopyDetached "copy_detached. Can only copy goal")
 
 
 let replay_proof_attempt c pr limit (id: proofNodeID) ~callback =

src/session/session_itp.ml

@@ -568,7 +568,7 @@ let copy_proof_node_as_detached (s: session) (pn_id: proofNodeID) =
   let new_goal = Ident.id_register (Ident.id_clone pn.proofn_name) in
   let checksum = pn.proofn_checksum in
   let shape = pn.proofn_shape in
-  let _ = mk_proof_node_no_task s new_goal parent new_pn_id checksum shape in
+  let (_: unit) = mk_proof_node_no_task s new_goal parent new_pn_id checksum shape in
   graft_detached_proof_on_parent s new_pn_id parent;
   new_pn_id
 
@@ -602,7 +602,7 @@ let mk_transf_node (s : session) (id : proofNodeID) (node_id : transID)
   Hint.add s.trans_table node_id tn;
   pn.proofn_transformations <- node_id::pn.proofn_transformations
 
-exception BadCopyDetached
+exception BadCopyDetached of string
 
 let rec copy_structure ~notification s from_any to_any : unit =
   match from_any, to_any with
@@ -637,7 +637,7 @@ let rec copy_structure ~notification s from_any to_any : unit =
         pn_id) sub_tasks in
     let tr = get_transfNode s to_tn in
     tr.transf_detached_subtasks <- new_sub_tasks
-  | _ -> raise BadCopyDetached
+  | _ -> raise (BadCopyDetached "copy_structure")
 
 let graft_transf  (s : session) (id : proofNodeID) (name : string)
     (args : string list) (tl : Task.task list) =

src/session/session_itp.mli

@@ -98,7 +98,7 @@ val get_any_parent: session -> any -> any option
 (* Answers true if a node is in a detached subtree *)
 val is_detached: session -> any -> bool
 
-exception BadCopyDetached
+exception BadCopyDetached of string
 
 (** [copy s pn] copy pn and add the copy as detached subgoal of its parent *)
 val copy_proof_node_as_detached: session -> proofNodeID -> proofNodeID