1 files changed, 33 insertions, 10 deletions

diff --git a/Python/getargs.c b/Python/getargs.c
index 550d0df..c491169 100644
--- a/Python/getargs.c
+++ b/Python/getargs.c
@@ -613,11 +613,21 @@ convertitem(PyObject *arg, const char **p_format, va_list *p_va, int flags,
 /* Format an error message generated by convertsimple(). */
 
 void
-_PyArg_BadArgument(const char *fname, const char *expected, PyObject *arg)
+_PyArg_BadArgument(const char *fname, int iarg,
+                   const char *expected, PyObject *arg)
 {
-    PyErr_Format(PyExc_TypeError, "%.200s() argument must be %.50s, not %.50s",
-                 fname, expected,
-                 arg == Py_None ? "None" : arg->ob_type->tp_name);
+    if (iarg) {
+        PyErr_Format(PyExc_TypeError,
+                     "%.200s() argument %d must be %.50s, not %.50s",
+                     fname, iarg, expected,
+                     arg == Py_None ? "None" : arg->ob_type->tp_name);
+    }
+    else {
+        PyErr_Format(PyExc_TypeError,
+                     "%.200s() argument must be %.50s, not %.50s",
+                     fname, expected,
+                     arg == Py_None ? "None" : arg->ob_type->tp_name);
+    }
 }
 
 static const char *
@@ -2416,13 +2426,12 @@ err:
 }
 
 
-static int
-unpack_stack(PyObject *const *args, Py_ssize_t nargs, const char *name,
-             Py_ssize_t min, Py_ssize_t max, va_list vargs)
-{
-    Py_ssize_t i;
-    PyObject **o;
+#undef _PyArg_CheckPositional
 
+int
+_PyArg_CheckPositional(const char *name, Py_ssize_t nargs,
+                       Py_ssize_t min, Py_ssize_t max)
+{
     assert(min >= 0);
     assert(min <= max);
 
@@ -2460,6 +2469,20 @@ unpack_stack(PyObject *const *args, Py_ssize_t nargs, const char *name,
         return 0;
     }
 
+    return 1;
+}
+
+static int
+unpack_stack(PyObject *const *args, Py_ssize_t nargs, const char *name,
+             Py_ssize_t min, Py_ssize_t max, va_list vargs)
+{
+    Py_ssize_t i;
+    PyObject **o;
+
+    if (!_PyArg_CheckPositional(name, nargs, min, max)) {
+        return 0;
+    }
+
     for (i = 0; i < nargs; i++) {
         o = va_arg(vargs, PyObject **);
         *o = args[i];