Issue #25270: Prevent codecs.escape_encode() from raising SystemError when an empty bytestring is passed

1 files changed, 14 insertions, 5 deletions

diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c
index 5934336..3934328 100644
--- a/Objects/bytesobject.c
+++ b/Objects/bytesobject.c
@@ -3550,11 +3550,15 @@ _PyBytes_Resize(PyObject **pv, Py_ssize_t newsize)
     PyObject *v;
     PyBytesObject *sv;
     v = *pv;
-    if (!PyBytes_Check(v) || Py_REFCNT(v) != 1 || newsize < 0) {
-        *pv = 0;
-        Py_DECREF(v);
-        PyErr_BadInternalCall();
-        return -1;
+    if (!PyBytes_Check(v) || newsize < 0) {
+        goto error;
+    }
+    if (Py_SIZE(v) == newsize) {
+        /* return early if newsize equals to v->ob_size */
+        return 0;
+    }
+    if (Py_REFCNT(v) != 1) {
+        goto error;
     }
     /* XXX UNREF/NEWREF interface should be more symmetrical */
     _Py_DEC_REFTOTAL;
@@ -3572,6 +3576,11 @@ _PyBytes_Resize(PyObject **pv, Py_ssize_t newsize)
     sv->ob_sval[newsize] = '\0';
     sv->ob_shash = -1;          /* invalidate cached hash value */
     return 0;
+error:
+    *pv = 0;
+    Py_DECREF(v);
+    PyErr_BadInternalCall();
+    return -1;
 }
 
 void