add_obj is ATOMIC

diff --git a/helm/matita/matitaSync.ml b/helm/matita/matitaSync.ml
index 51007df29ea5a64a74986770a754bda14bb269b5..e12c1cd146c11506322c8c19514c8d6e1bb9209e 100644 (file)
--- a/helm/matita/matitaSync.ml
+++ b/helm/matita/matitaSync.ml
@@ -155,13 +155,25 @@ let add_obj uri obj status =
   if CicEnvironment.in_library uri then
     command_error (sprintf "%s already defined" suri)
   else begin
-    CicTypeChecker.typecheck_obj uri obj;
-    MetadataDb.index_obj ~dbd ~uri; (* must be in the env *)
-    let new_stuff = save_object_to_disk status uri obj in  
-    MatitaLog.message (sprintf "%s defined" suri);
-    let status = add_aliases_for_object status suri obj in
-    { status with objects = new_stuff @ status.objects;
-                  proof_status = No_proof }
+    CicTypeChecker.typecheck_obj uri obj; (* 1 *)
+    try 
+      MetadataDb.index_obj ~dbd ~uri; (* 2 must be in the env *)
+      try
+        let new_stuff = save_object_to_disk status uri obj in (* 3 *)
+        try 
+          MatitaLog.message (sprintf "%s defined" suri);
+          let status = add_aliases_for_object status suri obj in
+          { status with objects = new_stuff @ status.objects;
+                        proof_status = No_proof }
+        with exc ->
+          List.iter MatitaMisc.safe_remove (List.map snd new_stuff); (* -3 *)
+          raise exc
+      with exc ->
+        ignore(MatitaDb.remove_uri uri); (* -2 *)
+        raise exc
+    with exc ->
+      CicEnvironment.remove_obj uri; (* -1 *)
+      raise exc
   end
    
 module OrderedUri =