[PyChecker-list] Simple nested func situation that breaks pychecker but hard

[Drumheller, M. <mic...@bo...>]

Below is a description of a pychecker bug that I have run across.

(Believe it or not, I do have a good reason for nesting this many
function definitions.  Note that it is perfectly legal Python that does
exactly what I want it to do--in its real context; I have merely
abstracted it here for simplicity.)

Thank you.

Michael Drumheller
The Boeing Company
Seattle, Washington

P.S.  (Actually, it's two bugs:  The parameter y *is* used, despite the
warning message.)

-------------pychecker version---------
0.8.14
-------------code:  foo.py-------------
def f(x):
    def g(y):
        def h(z):
            x.m(y, z)
        return h
    return g
--------------pychecker trace----------
Warnings...

foo.py:2: Parameter (y) not used
foo.py:3: INTERNAL ERROR -- STOPPED PROCESSING FUNCTION --
	Traceback (most recent call last):
	  File "c:\Python24\lib\site-packages\pychecker\warn.py", line
220, in _checkFunction
	    _handleNestedCode(func_code, code, codeSource)
	  File "c:\Python24\lib\site-packages\pychecker\warn.py", line
170, in _handleNestedCode
	    _checkCode(code, codeSource)
	  File "c:\Python24\lib\site-packages\pychecker\warn.py", line
144, in _checkCode
	    dispatch_func(oparg, operand, codeSource, code)
	  File "c:\Python24\lib\site-packages\pychecker\CodeChecks.py",
line 1041, in _LOAD_DEREF
	    argname =3D func_code.co_freevars[oparg -
len(func_code.co_cellvars)]
	IndexError: tuple index out of range
=09
Processing foo...
-------------end trace-----------------------------