Be more careful with negative reference counts.

diff --git a/Include/object.h b/Include/object.h
index 465617389ef1267bccbc9809abf31e95c43344e1..7147339923ecac81aede200660d71e25fb006d6f 100644 (file)
--- a/Include/object.h
+++ b/Include/object.h
@@ -56,7 +56,7 @@ whose size is determined when the object is allocated.
 #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 @@ extern long ref_total;
 #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 @@ extern long ref_total;
 #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)