Fix CVE-2021-3177 for Python 2.7:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3177

Patch copied from Debian:

https://salsa.debian.org/cpython-team/python2/-/blob/e54f3303884f1362f3311ec36f070b40603dd76e/debian/patches/CVE-2021-3177.diff

bpo-42938: Replace snprintf with Python unicode formatting in ctypes param reprs.
--- a/Lib/ctypes/test/test_parameters.py
+++ b/Lib/ctypes/test/test_parameters.py
@@ -206,6 +206,49 @@ class SimpleTypesTestCase(unittest.TestC
         with self.assertRaises(ZeroDivisionError):
             WorseStruct().__setstate__({}, b'foo')
 
+    def test_parameter_repr(self):
+        from ctypes import (
+            c_bool,
+            c_char,
+            c_wchar,
+            c_byte,
+            c_ubyte,
+            c_short,
+            c_ushort,
+            c_int,
+            c_uint,
+            c_long,
+            c_ulong,
+            c_longlong,
+            c_ulonglong,
+            c_float,
+            c_double,
+            c_longdouble,
+            c_char_p,
+            c_wchar_p,
+            c_void_p,
+        )
+        self.assertRegexpMatches(repr(c_bool.from_param(True)), r"^<cparam '\?' at 0x[A-Fa-f0-9]+>$")
+        self.assertEqual(repr(c_char.from_param('a')), "<cparam 'c' (a)>")
+        self.assertRegexpMatches(repr(c_wchar.from_param('a')), r"^<cparam 'u' at 0x[A-Fa-f0-9]+>$")
+        self.assertEqual(repr(c_byte.from_param(98)), "<cparam 'b' (98)>")
+        self.assertEqual(repr(c_ubyte.from_param(98)), "<cparam 'B' (98)>")
+        self.assertEqual(repr(c_short.from_param(511)), "<cparam 'h' (511)>")
+        self.assertEqual(repr(c_ushort.from_param(511)), "<cparam 'H' (511)>")
+        self.assertRegexpMatches(repr(c_int.from_param(20000)), r"^<cparam '[li]' \(20000\)>$")
+        self.assertRegexpMatches(repr(c_uint.from_param(20000)), r"^<cparam '[LI]' \(20000\)>$")
+        self.assertRegexpMatches(repr(c_long.from_param(20000)), r"^<cparam '[li]' \(20000\)>$")
+        self.assertRegexpMatches(repr(c_ulong.from_param(20000)), r"^<cparam '[LI]' \(20000\)>$")
+        self.assertRegexpMatches(repr(c_longlong.from_param(20000)), r"^<cparam '[liq]' \(20000\)>$")
+        self.assertRegexpMatches(repr(c_ulonglong.from_param(20000)), r"^<cparam '[LIQ]' \(20000\)>$")
+        self.assertEqual(repr(c_float.from_param(1.5)), "<cparam 'f' (1.5)>")
+        self.assertEqual(repr(c_double.from_param(1.5)), "<cparam 'd' (1.5)>")
+        self.assertEqual(repr(c_double.from_param(1e300)), "<cparam 'd' (1e+300)>")
+        self.assertRegexpMatches(repr(c_longdouble.from_param(1.5)), r"^<cparam ('d' \(1.5\)|'g' at 0x[A-Fa-f0-9]+)>$")
+        self.assertRegexpMatches(repr(c_char_p.from_param(b'hihi')), "^<cparam 'z' \(0x[A-Fa-f0-9]+\)>$")
+        self.assertRegexpMatches(repr(c_wchar_p.from_param('hihi')), "^<cparam 'Z' \(0x[A-Fa-f0-9]+\)>$")
+        self.assertRegexpMatches(repr(c_void_p.from_param(0x12)), r"^<cparam 'P' \(0x0*12\)>$")
+
 ################################################################
 
 if __name__ == '__main__':
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -460,50 +460,53 @@ PyCArg_dealloc(PyCArgObject *self)
 static PyObject *
 PyCArg_repr(PyCArgObject *self)
 {
-    char buffer[256];
     switch(self->tag) {
     case 'b':
     case 'B':
-        sprintf(buffer, "<cparam '%c' (%d)>",
+        return PySt<tr><td class='mode'>-rw-r--r--</td><td class='upd'><a href='/guix/diff/gnu/packages/python-web.scm?id=0021363d1bcfd6c5beec37e21f2292b2917d79cd'>gnu/packages/python-web.scm</a></td><td class='right'>32</td><td class='graph'><table summary='file diffstat' width='32%'><tr><td class='add' style='width: 100.0%;'/><td class='rem' style='width: 0.0%;'/><td class='none' style='width: 0.0%;'/></tr></table></td></tr>
</table><div class='diffstat-summary'>1 files changed, 32 insertions, 0 deletions</div><table summary='diff' class='diff'><tr><td><div class='head'>diff --git a/gnu/packages/python-web.scm b/gnu/packages/python-web.scm<br/>index 9464021d82..ac7ea63573 100644<br/>--- a/<a href='/guix/tree/gnu/packages/python-web.scm?id=e4a88925b44c7463e0a9c43e1715605c73b77e65'>gnu/packages/python-web.scm</a><br/>+++ b/<a href='/guix/tree/gnu/packages/python-web.scm?id=0021363d1bcfd6c5beec37e21f2292b2917d79cd'>gnu/packages/python-web.scm</a></div><div class='hunk'>@@ -31,6 +31,7 @@</div><div class='ctx'> ;;; Copyright © 2019 Brendan Tildesley &lt;mail@brendan.scot&gt;</div><div class='ctx'> ;;; Copyright © 2019 Pierre Langlois &lt;pierre.langlois@gmx.com&gt;</div><div class='ctx'> ;;; Copyright © 2019 Tanguy Le Carrour &lt;tanguy@bioneland.org&gt;</div><div class='add'>+;;; Copyright © 2020 Jakub Kądziołka &lt;kuba@kadziolka.net&gt;</div><div class='ctx'> ;;;</div><div class='ctx'> ;;; This file is part of GNU Guix.</div><div class='ctx'> ;;;</div><div class='hunk'>@@ -3494,3 +3495,34 @@ is part of the Weblate translation platform.")</div><div class='ctx'>     (description "This package provides an extended library for interacting</div><div class='ctx'> with GitLab instances through their API.")</div><div class='ctx'>     (license license:lgpl3+)))</div><div class='add'>+</div><div class='add'>+(define-public python-path-and-address</div><div class='add'>+  (package</div><div class='add'>+    (name "python-path-and-address")</div><div class='add'>+    (version "2.0.1")</div><div class='add'>+    (source</div><div class='add'>+     (origin</div><div class='add'>+       ;; The source distributed on PyPI doesn't include tests.</div><div class='add'>+       (method git-fetch)</div><div class='add'>+       (uri (git-reference</div><div class='add'>+             (url "https://github.com/joeyespo/path-and-address")</div><div class='add'>+             (commit (string-append "v" version))))</div><div class='add'>+       (file-name (git-file-name name version))</div><div class='add'>+       (sha256</div><div class='add'>+        (base32</div