While working with Python, a co-worker found a puzzling behavior… He couldn’t get correct slices on an object he created. After puzzling over the problem, we found out the problem – __getslice__ seems to change its arguments: in a 32 bit argument, when the MSB is set, the argument is changed to 0x7FFFFFFF. After looking it up, it turned out that the bug was also present in the latest Python 2.5. It also turned out that __getslice__ is deprecated. Here is the link to the bug info. This was the first time I got to submit a Python bug. Kind of a mixed feeling.
[Update: This bug was closed. You can still read about it in the original bug info.]