Merge pull request numpy#26027 from ngoldbaum/fix-stringdtype-cast-error-handling

BUG: add missing error handling in string to int cast internals

Author: seberg

numpy/_core/src/multiarray/stringdtype/casts.c

@@ -571,6 +571,9 @@ string_to_pylong(char *in, int has_null,
 {
     PyObject *val_obj = non_nullable_string_to_pystring(
             in, has_null, default_string, allocator);
+    if (val_obj == NULL) {
+        return NULL;
+    }
     // interpret as an integer in base 10
     PyObject *pylong_value = PyLong_FromUnicodeObject(val_obj, 10);
     Py_DECREF(val_obj);

numpy/_core/tests/test_stringdtype.py

@@ -546,6 +546,10 @@ def test_sized_integer_casts(bitsize, signed):
     with pytest.raises(OverflowError):
         np.array(oob, dtype="T").astype(idtype)
 
+    with pytest.raises(ValueError):
+        np.array(["1", np.nan, "3"],
+                 dtype=StringDType(na_object=np.nan)).astype(idtype)
+
 
 @pytest.mark.parametrize("typename", ["byte", "short", "int", "longlong"])
 @pytest.mark.parametrize("signed", ["", "u"])