[3.5] bpo-30708: Add private C API function _PyUnicode_AsWideCharString(). (GH-2285) (GH-2443) (#2448)

And use it instead of PyUnicode_AsWideCharString() if appropriate.

_PyUnicode_AsWideCharString(unicode) is like PyUnicode_AsWideCharString(unicode, NULL), but
raises a ValueError if the wchar_t* string contains null characters.
(cherry picked from commit e613e6add5f07ff6aad5802924596b631b707d2a).
(cherry picked from commit 0edffa3073b551ffeca34952529e7b292f1bd350)

1 files changed, 31 insertions, 0 deletions

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index d037d80..64375da 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -2839,6 +2839,37 @@ PyUnicode_AsWideCharString(PyObject *unicode,
     return buffer;
 }
 
+wchar_t*
+_PyUnicode_AsWideCharString(PyObject *unicode)
+{
+    const wchar_t *wstr;
+    wchar_t *buffer;
+    Py_ssize_t buflen;
+
+    if (unicode == NULL) {
+        PyErr_BadInternalCall();
+        return NULL;
+    }
+
+    wstr = PyUnicode_AsUnicodeAndSize(unicode, &buflen);
+    if (wstr == NULL) {
+        return NULL;
+    }
+    if (wcslen(wstr) != (size_t)buflen) {
+        PyErr_SetString(PyExc_ValueError,
+                        "embedded null character");
+        return NULL;
+    }
+
+    buffer = PyMem_NEW(wchar_t, buflen + 1);
+    if (buffer == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    memcpy(buffer, wstr, (buflen + 1) * sizeof(wchar_t));
+    return buffer;
+}
+
 #endif /* HAVE_WCHAR_H */
 
 PyObject *