[New-bugs-announce] [issue4379] Py_SAFE_DOWNCAST in FILE_TIME_to_time_t_nsec failing

[Kevin Watters]

New submission from Kevin Watters <kevinwatters at gmail.com>:

After releasing a Py_DEBUG build to some users who were experiencing 
problems, I noticed a pattern in some of the crash reports I got back:

msvcr90d!_wassert+0xb64
python25_d!FILE_TIME_to_time_t_nsec+0xac
python25_d!attribute_data_to_stat+0x67
python25_d!win32_wstat+0x6f
python25_d!posix_do_stat+0x51
python25_d!posix_stat+0x24
python25_d!PyCFunction_Call+0x65
python25_d!call_function+0x34f
python25_d!PyEval_EvalFrameEx+0x4741

The only way I can see _wassert being hit in FILE_TIME_to_time_t_nsec is 
in the Py_SAFE_DOWNCAST used to downcast an __int64 to int. 
Py_SAFE_DOWNCAST checks that there is equality between the casted and 
non-casted values with Py_DEBUG enabled--maybe in this function we 
should remove Py_SAFE_DOWNCAST?

I can't find a way to see the actual value for "in" before the assert is 
hit--I'm unfamiliar with picking through minidumps with WinDbg, which 
for some reason will show me the stack for these dumps when Visual 
Studio won't. But if I need to investigate more about them I can.

----------
components: None
messages: 76193
nosy: kevinwatters
severity: normal
status: open
title: Py_SAFE_DOWNCAST in FILE_TIME_to_time_t_nsec failing
type: behavior
versions: Python 2.5.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue4379>
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