Fix CRT SECURE warning in winutil

src/calibre/test_build.py

@@ -12,7 +12,7 @@
 Test a binary calibre build to ensure that all needed binary images/libraries have loaded.
 '''
 
-import os, ctypes, sys, unittest
+import os, ctypes, sys, unittest, time
 from calibre.constants import plugins, iswindows, islinux, isosx
 is_ci = os.environ.get('CI', '').lower() == 'true'
 
@@ -135,6 +135,16 @@ def au(x, name):
             au(v, k)
         for k in os.environ.keys():
             au(winutil.getenv(unicode(k)), 'getenv-' + k)
+        os.environ['XXXTEST'] = 'YYY'
+        self.assertEqual(winutil.getenv(u'XXXTEST'), u'YYY')
+        del os.environ['XXXTEST']
+        self.assertIsNone(winutil.getenv(u'XXXTEST'))
+        t = time.localtime()
+        fmt = u'%Y%a%b%e%H%M'
+        for fmt in (fmt, fmt.encode('ascii')):
+            x = winutil.strftime(fmt, t)
+            au(x, 'strftime')
+            self.ae(unicode(time.strftime(fmt, t)), x)
 
     def test_sqlite(self):
         import sqlite3

src/calibre/utils/windows/winutil.c

@@ -232,11 +232,15 @@ winutil_set_max_stdio(PyObject *self, PyObject *args) {
 
 static PyObject *
 winutil_getenv(PyObject *self, PyObject *args) {
-    const wchar_t *q;
+    const Py_UNICODE *q;
     if (!PyArg_ParseTuple(args, "u", &q)) return NULL;
-    wchar_t *ans = _wgetenv(q);
-    if (ans == NULL) Py_RETURN_NONE;
-    return PyUnicode_FromWideChar(ans, wcslen(ans));
+    wchar_t *buf = NULL;
+    size_t sz = 0;
+    PyObject *ans = NULL;
+    if (_wdupenv_s(&buf, &sz, q) != 0 || buf == NULL) { ans = Py_NONE; Py_INCREF(ans); }
+    else ans = PyUnicode_FromWideChar(buf, sz);
+    if (buf) free(buf);
+    return ans;
 }
 
 static PyObject*