PyArg_ParseTuple(args, "u#", ...) misbehaves with -Werror #94864

jwilk · 2022-07-14T19:45:28Z

PyArg_ParseTuple(args, "u#", ...) generates a deprecation warning, as expected:

$ python3 --version
Python 3.11.0b4
$ python3 -c 'import _testcapi as t; t.getargs_u_hash("")'
<string>:1: DeprecationWarning: getargs: The 'u' format is deprecated. Use 'U' instead.

But when I turn warnings into exceptions, something weird happens:

$ python3 -Werror -c 'import _testcapi as t; t.getargs_u_hash("")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ValueError: character U+b4000360 is not in range [U+0000; U+10ffff]

What's going on here? The code for getargs_u_hash() looks like this:

Py_UNICODE *str;
Py_ssize_t size;
if (!PyArg_ParseTuple(args, "u#", &str, &size))
    return NULL;
return PyUnicode_FromWideChar(str, size);

So it looks like PyArg_ParseTuple() returns true, but leaves str and size uninitialized.

The text was updated successfully, but these errors were encountered:

… "Z" It returned 1 (success) when warnings are turned into exceptions.

… "Z" (pythonGH-94902) It returned 1 (success) when warnings are turned into exceptions. (cherry picked from commit 107c21c) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

…H-94902) It returned 1 (success) when warnings are turned into exceptions.

…H-94902) It returned 1 (success) when warnings are turned into exceptions. (cherry picked from commit 107c21c) Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

serhiy-storchaka self-assigned this Jul 16, 2022

serhiy-storchaka added the 3.11 bug and security fixes label Jul 16, 2022

serhiy-storchaka added a commit to serhiy-storchaka/cpython that referenced this issue Jul 16, 2022

pythongh-94864: Fix PyArg_Parse* with deprecated format units "u" and…

e446f95

… "Z" It returned 1 (success) when warnings are turned into exceptions.

This was referenced Jul 16, 2022

[3.11] gh-94864: Fix PyArg_Parse* with deprecated format units "u" and "Z" #94902

Merged

[3.10] gh-94864: Fix PyArg_Parse* with deprecated format units "u" and "Z" (GH-94902) #94922

Merged

serhiy-storchaka added a commit that referenced this issue Jul 17, 2022

gh-94864: Fix PyArg_Parse* with deprecated format units "u" and "Z" (G…

107c21c

…H-94902) It returned 1 (success) when warnings are turned into exceptions.

serhiy-storchaka added the 3.10 bug and security fixes label Jul 17, 2022

serhiy-storchaka closed this as completed Jul 17, 2022

PyArg_ParseTuple(args, "u#", ...) misbehaves with -Werror #94864

PyArg_ParseTuple(args, "u#", ...) misbehaves with -Werror #94864

Comments

jwilk commented Jul 14, 2022