Issue #12909: Raise TypeError instead of SystemError when PyLong_AsDouble() or
PyLong_AsUnsignedLongLong() is passed a non-integer argument (to be consistent
with all the other PyLong_AsFoo() functions).


diff --git a/Objects/longobject.c b/Objects/longobject.c
--- a/Objects/longobject.c
+++ b/Objects/longobject.c
@@ -1193,10 +1193,14 @@
     int one = 1;
     int res;
 
-    if (vv == NULL || !PyLong_Check(vv)) {
+    if (vv == NULL) {
         PyErr_BadInternalCall();
         return (unsigned PY_LONG_LONG)-1;
     }
+    if (!PyLong_Check(vv)) {
+        PyErr_SetString(PyExc_TypeError, "an integer is required");
+        return (unsigned PY_LONG_LONG)-1;
+    }
 
     v = (PyLongObject*)vv;
     switch(Py_SIZE(v)) {
@@ -2481,10 +2485,14 @@
     Py_ssize_t exponent;
     double x;
 
-    if (v == NULL || !PyLong_Check(v)) {
+    if (v == NULL) {
         PyErr_BadInternalCall();
         return -1.0;
     }
+    if (!PyLong_Check(v)) {
+        PyErr_SetString(PyExc_TypeError, "an integer is required");
+        return -1.0;
+    }
     x = _PyLong_Frexp((PyLongObject *)v, &exponent);
     if ((x == -1.0 && PyErr_Occurred()) || exponent > DBL_MAX_EXP) {
         PyErr_SetString(PyExc_OverflowError,