merge changes from ocaml3110 to ocaml3111rc0

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@9270 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 9 insertions, 3 deletions

diff --git a/stdlib/parsing.ml b/stdlib/parsing.ml
index 2b4d93ddb..44c7fb271 100644
--- a/stdlib/parsing.ml
+++ b/stdlib/parsing.ml
@@ -180,9 +180,15 @@ let peek_val env n =
   Obj.magic env.v_stack.(env.asp - n)
 
 let symbol_start_pos () =
-  if env.rule_len > 0
-  then env.symb_start_stack.(env.asp - env.rule_len + 1)
-  else env.symb_end_stack.(env.asp)
+  let rec loop i =
+    if i <= 0 then env.symb_end_stack.(env.asp)
+    else begin
+      let st = env.symb_start_stack.(env.asp - i + 1) in
+      let en = env.symb_end_stack.(env.asp - i + 1) in
+      if st <> en then st else loop (i - 1)
+    end
+  in
+  loop env.rule_len
 ;;
 let symbol_end_pos () = env.symb_end_stack.(env.asp);;
 let rhs_start_pos n = env.symb_start_stack.(env.asp - (env.rule_len - n));;