[3.10] Fix a potential reference-counting bug in long_pow (pythonGH-26690)

mdickinson · mdickinson · commit def92d7fff18 · 2021-06-13T08:34:31.000+01:00
(cherry picked from commit 5924243) Co-authored-by: Mark Dickinson <mdickinson@enthought.com>
diff --git a/Objects/longobject.c b/Objects/longobject.c
@@ -4185,6 +4185,7 @@ long_pow(PyObject *v, PyObject *w, PyObject *x)
                 goto Error;
             Py_DECREF(a);
             a = temp;
+            temp = NULL;
         }
 
         /* Reduce base by modulus in some cases:

Original file line number	Diff line number	Diff line change
`@@ -4185,6 +4185,7 @@ long_pow(PyObject v, PyObject w, PyObject *x)`
`4185`	`4185`	`goto Error;`
`4186`	`4186`	`Py_DECREF(a);`
`4187`	`4187`	`a = temp;`
	`4188`	`+ temp = NULL;`
`4188`	`4189`	`}`
`4189`	`4190`
`4190`	`4191`	`/* Reduce base by modulus in some cases:`