PEP 757: PyLong_Export() can fail (#4025)

gmpy2: mpz_set_PyLong() now returns -1 on error.

Author: vstinner

peps/pep-0757.rst

@@ -147,9 +147,6 @@ Export API
    On success, set *\*export_long* and return 0.
    On error, set an exception and return -1.
 
-   This function always succeeds if *obj* is a Python :class:`int` object or a
-   subclass.
-
    If *export_long->digits* is not ``NULL``, :c:func:`PyLong_FreeExport` must be
    called when the export is no longer needed.
 
@@ -264,12 +261,15 @@ Export: :c:func:`PyLong_Export()` with gmpy2
 
 Code::
 
-    static void
+    static int
     mpz_set_PyLong(mpz_t z, PyObject *obj)
     {
         static PyLongExport long_export;
 
-        PyLong_Export(obj, &long_export);
+        if (PyLong_Export(obj, &long_export) < 0) {
+            return -1;
+        }
+
         if (long_export.digits) {
             mpz_import(z, long_export.ndigits, int_digits_order, int_digit_size,
                        int_endianness, int_nails, long_export.digits);
@@ -295,6 +295,7 @@ Code::
                 }
             }
         }
+        return 0;
     }
 
 Reference code: `mpz_set_PyLong() in the gmpy2 master for commit 9177648