Fix GC_make_descriptor for zero length argument

* typd_mlc.c (GC_make_descriptor): Cast len variable to signed_word.

1 files changed, 1 insertions, 1 deletions

diff --git a/typd_mlc.c b/typd_mlc.c
index 4019c50a..52a9bd11 100644
--- a/typd_mlc.c
+++ b/typd_mlc.c
@@ -507,7 +507,7 @@ STATIC mse * GC_array_mark_proc(word * addr, mse * mark_stack_ptr,
 
 GC_API GC_descr GC_CALL GC_make_descriptor(const GC_word * bm, size_t len)
 {
-    signed_word last_set_bit = len - 1;
+    signed_word last_set_bit = (signed_word)len - 1;
     GC_descr result;
     DCL_LOCK_STATE;