New submission from Alexis Daboville:


It looks like using a very long list of elif makes CPython segfault. You can 
try it with the attached file, which looks like this:

if False:
elif False:
   # thousands of elifs
elif False:

$ python
Segmentation fault.

CPython versions tested:
3.x (all segfaults):
3.1 on Debian
3.2 on Arch Linux
3.3 on Windows

2.6 on Debian: segfaults with a longer list of elifs than the one in the 
attached file.

The PyPy behaviour seems better: it raises 'RuntimeError: maximum recursion 
depth exceeded'.

A possible cause (if I understood 
<> well) is that 
there are no elif nodes in the AST, elif are just plain ifs which are stored 
recursively in the else part of the previous if.

(I'm not sure if that's an issue as it's not a real use case, but it makes 
CPython segfault and I was advised on #python-fr to report it anyway.)

messages: 176081
nosy: alexis.d
priority: normal
severity: normal
status: open
title: (very) long list of elif causes segfault
versions: Python 3.1, Python 3.2, Python 3.3
Added file:

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