[pypy-issue] Issue #2058: tkinter TypeError (pypy/pypy)

[Kevin Ednalino]

New issue 2058: tkinter TypeError
https://bitbucket.org/pypy/pypy/issue/2058/tkinter-typeerror

Kevin Ednalino:

Using pypy3 Linux 64-bit:
```
#!python

3.2.5 (b2091e973da69152b3f928bfaabd5d2347e6df46, Nov 18 2014, 20:15:54)
[PyPy 2.4.0 with GCC 4.9.2]
```

The exception:
```
#!python

Exception in Tkinter callback
Traceback (most recent call last):
  File "/opt/pypy3/lib-python/3/tkinter/__init__.py", line 1455, in __call__
    args = self.subst(*args)
  File "/opt/pypy3/lib-python/3/tkinter/__init__.py", line 1193, in _substitute
    try: e.focus = getboolean(f)
  File "/opt/pypy3/lib_pypy/_tkinter/app.py", line 442, in getboolean
    if '\x00' in s:
TypeError: 'str' does not support the buffer interface
```

This happens when using virtual events (through a widget's bind method).

The function where the error occurs:
```
#!python

def getboolean(self, s):
    if isinstance(s, int):
        return s
    s = s.encode('utf-8')
    if '\x00' in s:
        raise TypeError
    v = tkffi.new("int*")
    res = tklib.Tcl_GetBoolean(self.interp, s, v)
    if res == tklib.TCL_ERROR:
        self.raiseTclError()
    return bool(v[0])
```

The issue appears to be that *s* is a bytes object, so making *'\x00'* a bytes object fixes the issue:
```
#!python

    if b'\x00' in s:
```
Or another solution would be to check before encoding.

As far as I know, there are a couple other methods in the same class that have a similar pattern and would probably raise an exception also.