CR

Author: hhugo

compiler/lib/source_map.ml

@@ -394,15 +394,16 @@ module Standard = struct
                   ; names = List.rev_append sm.names acc_rev.names
                   ; sources_content =
                       (match acc_rev.sources_content with
-                      | Some acc_rev -> (
-                          match sm.sources_content with
-                          | Some x -> Some (List.rev_append x acc_rev)
-                          | None _ ->
-                              Some
-                                (List.rev_append
-                                   (List.map sm.sources ~f:(fun _ -> None))
-                                   acc_rev)
-                          | None -> None))
+                      | Some acc_rev ->
+                          let contents =
+                            match sm.sources_content with
+                            | Some x ->
+                                assert (List.length x = List.length sm.sources);
+                                x
+                            | None -> List.map sm.sources ~f:(fun _ -> None)
+                          in
+                          Some (List.rev_append contents acc_rev)
+                      | None -> None)
                   ; mappings = Mappings.empty
                   }
                 , List.rev_append_map