commit 2590fed7a355a421f062ebd4293df892800fa7ac
Author: Sebastian Rasmussen <sebras@gmail.com>
Date:   Thu Dec 1 17:15:27 2016 -0500

    Bug 697400: Mark visited objects when counting OCG layer entries.

diff --git a/source/pdf/pdf-layer.c b/source/pdf/pdf-layer.c
index 3296b6c..fc29c9d 100644
--- a/source/pdf/pdf-layer.c
+++ b/source/pdf/pdf-layer.c
@@ -90,7 +90,14 @@ count_entries(fz_context *ctx, pdf_obj *obj)
 	for (i = 0; i < len; i++)
 	{
 		pdf_obj *o = pdf_array_get(ctx, obj, i);
-		count += (pdf_is_array(ctx, o) ? count_entries(ctx, o) : 1);
+		if (pdf_mark_obj(ctx, o))
+			continue;
+		fz_try(ctx)
+			count += (pdf_is_array(ctx, o) ? count_entries(ctx, o) : 1);
+		fz_always(ctx)
+			pdf_unmark_obj(ctx, o);
+		fz_catch(ctx)
+			fz_rethrow(ctx);
 	}
 	return count;
 }
@@ -106,7 +113,16 @@ populate_ui(fz_context *ctx, pdf_ocg_descriptor *desc, pdf_ocg_ui *ui, pdf_obj *
 		pdf_obj *o = pdf_array_get(ctx, order, i);
 		if (pdf_is_array(ctx, o))
 		{
-			ui = populate_ui(ctx, desc, ui, o, depth+1, rbgroups, locked);
+			if (pdf_mark_obj(ctx, o))
+				continue;
+
+			fz_try(ctx)
+				ui = populate_ui(ctx, desc, ui, o, depth+1, rbgroups, locked);
+			fz_always(ctx)
+				pdf_unmark_obj(ctx, o);
+			fz_catch(ctx)
+				fz_rethrow(ctx);
+
 			continue;
 		}
 		ui->depth = depth;