From 3ec9af75f6825a32f369ee182a388c365db241b6 Mon Sep 17 00:00:00 2001
From: Victor Stinner <vstinner@redhat.com>
Date: Fri, 26 Oct 2018 02:12:34 +0200
Subject: [PATCH] bpo-9263: _Py_NegativeRefcount() use _PyObject_AssertFailed()
 (GH-10109)

_Py_NegativeRefcount() now uses _PyObject_AssertFailed() to dump the
object to help debugging.
---
 Lib/test/test_capi.py |  5 +++--
 Objects/object.c      | 13 +++++--------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index a732f4f82f..b3600ebe99 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -329,8 +329,9 @@ class CAPITest(unittest.TestCase):
         """)
         rc, out, err = assert_python_failure('-c', code)
         self.assertRegex(err,
-                         br'_testcapimodule\.c:[0-9]+ object at .* '
-                         br'has negative ref count', err)
+                         br'_testcapimodule\.c:[0-9]+: '
+                         br'_Py_NegativeRefcount: Assertion ".*" failed; '
+                         br'object has negative ref count')
 
 
 class TestPendingCalls(unittest.TestCase):
diff --git a/Objects/object.c b/Objects/object.c
index 2252f98347..d6f27ff948 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -205,13 +205,9 @@ void dec_count(PyTypeObject *tp)
 void
 _Py_NegativeRefcount(const char *filename, int lineno, PyObject *op)
 {
-    char buf[300];
-
-    PyOS_snprintf(buf, sizeof(buf),
-                  "%s:%i object at %p has negative ref count "
-                  "%" PY_FORMAT_SIZE_T "d",
-                  filename, lineno, op, op->ob_refcnt);
-    Py_FatalError(buf);
+    _PyObject_AssertFailed(op, "object has negative ref count",
+                           "op->ob_refcnt >= 0",
+                           filename, lineno, __func__);
 }
 
 #endif /* Py_REF_DEBUG */
@@ -356,13 +352,14 @@ PyObject_Print(PyObject *op, FILE *fp, int flags)
         Py_END_ALLOW_THREADS
     }
     else {
-        if (op->ob_refcnt <= 0)
+        if (op->ob_refcnt <= 0) {
             /* XXX(twouters) cast refcount to long until %zd is
                universally available */
             Py_BEGIN_ALLOW_THREADS
             fprintf(fp, "<refcnt %ld at %p>",
                 (long)op->ob_refcnt, op);
             Py_END_ALLOW_THREADS
+        }
         else {
             PyObject *s;
             if (flags & Py_PRINT_RAW)
-- 
2.40.0