Be more careful with negative reference counts.
diff --git a/Include/object.h b/Include/object.h
index 4656173..7147339 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -56,7 +56,7 @@
#ifdef TRACE_REFS
#define OB_HEAD \
struct _object *_ob_next, *_ob_prev; \
- unsigned int ob_refcnt; \
+ int ob_refcnt; \
struct _typeobject *ob_type;
#define OB_HEAD_INIT(type) 0, 0, 1, type,
#else
@@ -200,7 +200,7 @@
#endif
#define INCREF(op) (ref_total++, (op)->ob_refcnt++)
#define DECREF(op) \
- if (--ref_total, --(op)->ob_refcnt != 0) \
+ if (--ref_total, --(op)->ob_refcnt > 0) \
; \
else \
DELREF(op)
@@ -208,7 +208,7 @@
#define NEWREF(op) ((op)->ob_refcnt = 1)
#define INCREF(op) ((op)->ob_refcnt++)
#define DECREF(op) \
- if (--(op)->ob_refcnt != 0) \
+ if (--(op)->ob_refcnt > 0) \
; \
else \
DELREF(op)