BUG, COMPAT: PyList_GET_SIZE works only by chance on ndarray

Author: mattip

pandas/_libs/src/ujson/python/JSONtoObj.c

@@ -409,7 +409,7 @@ JSOBJ Object_npyEndObject(void *prv, JSOBJ obj) {
 }
 
 int Object_npyObjectAddKey(void *prv, JSOBJ obj, JSOBJ name, JSOBJ value) {
- PyObject *label;
+ PyObject *label, *labels;
  npy_intp labelidx;
  // add key to label array, value to values array
  NpyArrContext *npyarr = (NpyArrContext *)obj;
@@ -424,11 +424,11 @@ int Object_npyObjectAddKey(void *prv, JSOBJ obj, JSOBJ name, JSOBJ value) {
  if (!npyarr->labels[labelidx]) {
  npyarr->labels[labelidx] = PyList_New(0);
  }
-
+ labels = npyarr->labels[labelidx];
  // only fill label array once, assumes all column labels are the same
  // for 2-dimensional arrays.
- if (PyList_GET_SIZE(npyarr->labels[labelidx]) <= npyarr->elcount) {
- PyList_Append(npyarr->labels[labelidx], label);
+ if (PyList_Check(labels) && PyList_GET_SIZE(labels) <= npyarr->elcount) {
+ PyList_Append(labels, label);
  }
 
  if (((JSONObjectDecoder *)npyarr->dec)->arrayAddItem(prv, obj, value)) {
@@ -439,16 +439,16 @@ int Object_npyObjectAddKey(void *prv, JSOBJ obj, JSOBJ name, JSOBJ value) {
 }
 
 int Object_objectAddKey(void *prv, JSOBJ obj, JSOBJ name, JSOBJ value) {
- PyDict_SetItem(obj, name, value);
+ int ret = PyDict_SetItem(obj, name, value);
  Py_DECREF((PyObject *)name);
  Py_DECREF((PyObject *)value);
- return 1;
+ return ret==0 ? 1 : 0;
 }
 
 int Object_arrayAddItem(void *prv, JSOBJ obj, JSOBJ value) {
- PyList_Append(obj, value);
+ int ret = PyList_Append(obj, value);
  Py_DECREF((PyObject *)value);
- return 1;
+ return ret==0 ? 1 : 0;
 }
 
 JSOBJ Object_newString(void *prv, wchar_t *start, wchar_t *end) {