From 34e3dbc6ba03a3c9ce7d2238b7ec98aea4a939ee Mon Sep 17 00:00:00 2001
From: Mark Wooding <mdw@distorted.org.uk>
Date: Sun, 24 Nov 2019 00:21:44 +0000
Subject: [PATCH] mp.c: Convert shift amounts via `index' to prevent `float'
 and `str'.

It obviously makes no sense to calculate `MP(4) << "4"' or `MP(9) >>
2.8'.
---
 mp.c | 27 +++++++++++++--------------
 1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/mp.c b/mp.c
index 96e3e86..c47b011 100644
--- a/mp.c
+++ b/mp.c
@@ -393,25 +393,24 @@ UNOP(mp, not2c)
 static PyObject *mp_pyid(PyObject *x) { RETURN_OBJ(x); }
 
 #define gf_lsr mp_lsr
-#define SHIFTOP(pre, name, rname)					\
+#define SHIFTOP(pre, PRE, name, rname)					\
   static PyObject *pre##_py##name(PyObject *x, PyObject *y) {		\
-    mp *xx, *yy;							\
+    PyObject *yix = 0;							\
     PyObject *z = 0;							\
     long n;								\
-    if (pre##binop(x, y, &xx, &yy)) RETURN_NOTIMPL;			\
-    if (mp_tolong_checked(yy, &n, 1)) goto end;				\
-    if (n < 0)								\
-      z = pre##_pywrap(mp_##rname(MP_NEW, xx, -n));			\
-    else								\
-      z = pre##_pywrap(mp_##name(MP_NEW, xx, n));			\
-  end:									\
-    MP_DROP(xx); MP_DROP(yy);						\
+    if (!PRE##_PYCHECK(x)) RETURN_NOTIMPL;				\
+    if (GF_PYCHECK(y) || FE_PYCHECK(y)) RETURN_NOTIMPL;			\
+    yix = PyNumber_Index(y); if (!yix) { PyErr_Clear(); RETURN_NOTIMPL; } \
+    n = PyInt_AsLong(yix); Py_DECREF(yix);				\
+    if (n == -1 && PyErr_Occurred())  { PyErr_Clear(); RETURN_NOTIMPL; } \
+    if (n < 0) z = pre##_pywrap(mp_##rname(MP_NEW, MP_X(x), -n));	\
+    else z = pre##_pywrap(mp_##name(MP_NEW, MP_X(x), n));		\
     return (z);								\
   }
-SHIFTOP(mp, lsl2c, lsr2c)
-SHIFTOP(mp, lsr2c, lsl2c)
-SHIFTOP(gf, lsl, lsr)
-SHIFTOP(gf, lsr, lsl)
+SHIFTOP(mp, MP, lsl2c, lsr2c)
+SHIFTOP(mp, MP, lsr2c, lsl2c)
+SHIFTOP(gf, GF, lsl, lsr)
+SHIFTOP(gf, GF, lsr, lsl)
 #undef SHIFTOP
 
 #define DIVOP(pre, name, qq, rr, gather)				\
-- 
2.11.0