[Patches] [ python-Patches-527371 ] Fix for sre bug 470582

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Patches item #527371, was opened at 2002-03-08 04:14
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Category: None
Group: None
Status: Open
Resolution: None
Priority: 5
Submitted By: Greg Chapman (glchapman)
Assigned to: Nobody/Anonymous (nobody)
Summary: Fix for sre bug 470582

Initial Comment:
Bug report 470582 points out that nested groups can 
produces matches in sre even if the groups within 
which they are nested do not match:

>>> m = sre.search(r"^((\d)\:)?(\d\d)\.(\d\d\d)
$", "34.123")
>>> m.groups()
(None, '3', '34', '123')
>>> m = pre.search(r"^((\d)\:)?(\d\d)\.(\d\d\d)
$", "34.123")
>>> m.groups()
(None, None, '34', '123')

I believe this is because in the handling of 
SRE_OP_MAX_UNTIL, state->lastmark is being reduced 
(after "((\d)\:)" fails) without NULLing out the now-
invalid entries at the end of the state->mark array.  
In the other two cases where state->lastmark is 
reduced (specifically in SRE_OP_BRANCH and 
SRE_OP_REPEAT_ONE) memset is used to NULL out the 
entries at the end of the array.  The attached patch 
does the same thing for the SRE_OP_MAX_UNTIL case.  
This fixes the above case and does not break anything 
in test_re.py.


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>Comment By: Greg Chapman (glchapman)
Date: 2002-03-08 04:20

Message:
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I forgot: here's a patch for re_tests.py which adds the 
case from the bug report as a test.

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