Issue #8592: PyArg_Parse*() functions raise a TypeError for "y", "u" and "Z"
formats if the string contains a null byte/character. Write unit tests for
string formats.
diff --git a/Doc/c-api/arg.rst b/Doc/c-api/arg.rst
index ea897a8..1c49c8b 100644
--- a/Doc/c-api/arg.rst
+++ b/Doc/c-api/arg.rst
@@ -125,6 +125,8 @@
pointer variable, which will be filled with the pointer to an existing
Unicode buffer. Please note that the width of a :ctype:`Py_UNICODE`
character depends on compilation options (it is either 16 or 32 bits).
+ The Python string must not contain embedded NUL characters; if it does,
+ a :exc:`TypeError` exception is raised.
.. note::
Since ``u`` doesn't give you back the length of the string, and it