From 3139556838022a2699cb51c24241e207529e1c0f Mon Sep 17 00:00:00 2001
From: John Whitington <john@coherentgraphics.co.uk>
Date: Tue, 2 Jul 2019 18:37:08 +0100
Subject: [PATCH] Better verification of bookmark files

---
 cpdf.ml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cpdf.ml b/cpdf.ml
index ebf15d1..b48bd6d 100644
--- a/cpdf.ml
+++ b/cpdf.ml
@@ -984,7 +984,9 @@ let rec verify_bookmarks pdf lastlevel fastrefnums endpage = function
 let verify_bookmarks pdf lastlevel endpage marks =
   let refnums = Pdf.page_reference_numbers pdf in
   let fastrefnums = hashtable_of_dictionary (combine refnums (indx refnums)) in
-    verify_bookmarks pdf lastlevel fastrefnums endpage marks
+    match marks with
+    | [] -> true
+    | m::more -> m.Pdfmarks.level = 0 && verify_bookmarks pdf lastlevel fastrefnums endpage more
 
 (* Parse a line of the bookmarks file. *)