Imported Upstream version 8.0pl2upstream/8.0pl2

1 files changed, 8 insertions, 3 deletions

diff --git a/lib/compat.ml4 b/lib/compat.ml4
index 5e1c65b4..0947f5fb 100644
--- a/lib/compat.ml4
+++ b/lib/compat.ml4
@@ -11,19 +11,24 @@
 (* IFDEF not available in 3.06; use ifdef instead *)
 
 (* type loc is different in 3.08 *)
-ifdef OCAML308 then
+ifdef OCAML_308 then
 module M = struct
 type loc = Token.flocation
 let dummy_loc = Token.dummy_loc
-let unloc (b,e) = (b.Lexing.pos_cnum,e.Lexing.pos_cnum)
 let make_loc loc = Token.make_loc loc
+let unloc (b,e) =
+  let loc = (b.Lexing.pos_cnum,e.Lexing.pos_cnum) in
+  (* Ensure that we unpack a char location that was encoded as a line-col
+     location by make_loc *)
+  assert (dummy_loc = (b,e) or make_loc loc = (b,e));
+  loc
 end
 else
 module M = struct
 type loc = int * int
 let dummy_loc = (0,0)
-let unloc x = x
 let make_loc x = x
+let unloc x = x
 end
 
 type loc = M.loc