Fix hb_n_marks underflow in clear_fl_marks if MARK_BIT_PER_OBJ

Issue #177 (bdwgc).

* mark.c [MARK_BIT_PER_OBJ] (GC_set_hdr_marks): Set hhdr->hb_n_marks
exactly to n_marks value (without a decrement by one).

1 files changed, 1 insertions, 1 deletions

diff --git a/mark.c b/mark.c
index 33f2fba5..0fba5b81 100644
--- a/mark.c
+++ b/mark.c
@@ -166,7 +166,7 @@ GC_INNER void GC_set_hdr_marks(hdr *hhdr)
       }
 #   endif
 #   ifdef MARK_BIT_PER_OBJ
-      hhdr -> hb_n_marks = n_marks - 1;
+      hhdr -> hb_n_marks = n_marks;
 #   else
       hhdr -> hb_n_marks = HBLK_OBJS(sz);
 #   endif