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Bug#304296: marked as done (Segfault in CppOwnedDealloc<PkgSrcRecordsStruct>)

Your message dated Fri, 28 Jul 2006 17:20:58 +0200
with message-id <20060728152058.GA3291@orest.greek0.net>
and subject line Bug#304296: Segfault in CppOwnedDealloc<PkgSrcRecordsStruct>
has caused the attached Bug report to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
Bug report if necessary, and/or fix the problem forthwith.

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Debian bug tracking system administrator
(administrator, Debian Bugs database)
--- Begin Message --- 
Package: python-apt
Version: 0.6.10
Severity: normal
Tags: patch

I've hit a segfault python-apt while trying to write a class that
nicely encapsulates a package.

gdb says:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1075396736 (LWP 8931)]
0x403f20bc in CppOwnedDealloc<PkgSrcRecordsStruct> () from
/usr/lib/python2.3/site-packages/apt_pkg.so

Looking at the source (at python/pkgsrcrecords.cc) there's a
mismatch in the used variants of the object allocation/deallocation
functions. Allocation is done with CppPyObject_NEW, while
deallocation is done with CppOwnedDealloc. Using the non-owned
variants everywhere the segfault is gone. 

I've attatched the python program that triggered the segfault here,
and my proposed fix.

Cheers,
Greek0

-- System Information:
Debian Release: 3.1
  APT prefers unstable
  APT policy: (990, 'unstable'), (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.8r20050410
Locale: LANG=de_AT.UTF-8@euro, LC_CTYPE=de_AT.UTF-8@euro (charmap=UTF-8)

Versions of packages python-apt depends on:
ii  apt [libapt-pkg-libc6.3-5-3 0.5.28.6     Advanced front-end for dpkg
ii  apt-utils [libapt-inst-libc 0.5.28.6     APT utility programs
ii  libc6                       2.3.2.ds1-20 GNU C Library: Shared libraries an
ii  libgcc1                     1:3.4.3-12   GCC support library
ii  libstdc++5                  1:3.3.5-12   The GNU Standard C++ Library v3
ii  python                      2.3.5-2      An interactive high-level object-o

-- no debconf information

#!/usr/bin/env python2.4

import sys
import os
import re
import copy
import apt_pkg
import options

class Regexps:
	# apt-cache policy RE
	# Installed = groups(1)
	# Candidate = groups(2)
	policy = re.compile(r'^\s+Installed: (.*)$\n^\s+Candidate: (.*)$', re.M)

class Package(object):
	"""Maintains data about packages.

	This class encapsulates a package. It allows inspection of the current
	state, listing of available versions, ...

	>>> y = Package("kde")
	>>> y.is_installed()
	False
	>>> y.installed
	''
	>>> y.candidate
	'5:44'
	>>> y.source
	'xfree86'

	"""
	def __init__(self, pkgname):
		self._name = pkgname
		self._installed = None
		self._candidate = None
		self._source = None

	def _read_policy(self):
		args = ""
		if options.opts.Release != None:
			args += " -oAPT::Default-Release='%s' " % options.opts.Release

		cmdline = "apt-cache policy %s %s" % (args, self._name)

		f = os.popen(cmdline)
		policy_txt = f.read()
		f.close()

		match = Regexps.policy.search(policy_txt)
		if match.group(1) == "(none)":
			self._installed = ""
		else:
			self._installed = match.group(1)
		self._candidate = match.group(2)

	def _get_candidate(self):
		if self._candidate == None:
			self._read_policy()
		return self._candidate

	def _get_installed(self):
		if self._installed == None:
			self._read_policy()
		return self._installed

	def is_installed(self):
		if self._installed == None:
			self._read_policy()

		return bool(self._installed)

	def _get_source(self):
		if self._source == None:
			src = apt_pkg.GetPkgSrcRecords(apt_pkg.GetCache())
			src.Lookup(self._name)
			self._source = copy.deepcopy(src.Package)
			print self._source

		#return self._source


	candidate = property(_get_candidate)
	installed = property(_get_installed)
	source = property(_get_source)


def main():
	os.environ["LC_ALL"]="C"
	os.environ["LC_MESSAGES"]="C"
	options.ParseOptions()
	apt_pkg.init()
	p = Package("xterm")
	print "Installed: %s" % p.installed
	print "Candidate: %s" % p.candidate
	x = p.source
	print "x:"
	print x
	print "source:"
	print p._source

if __name__ == "__main__":
	main()

diff -ur orig.python-apt-0.6.10/python/pkgsrcrecords.cc python-apt-0.6.10/python/pkgsrcrecords.cc
--- orig.python-apt-0.6.10/python/pkgsrcrecords.cc	2003-12-26 18:04:22.000000000 +0100
+++ python-apt-0.6.10/python/pkgsrcrecords.cc	2005-04-12 08:48:46.640532096 +0200
@@ -89,10 +89,10 @@
    PyObject_HEAD_INIT(&PyType_Type)
    0,			                // ob_size
    "pkgSrcRecords",                          // tp_name
-   sizeof(CppOwnedPyObject<PkgSrcRecordsStruct>),   // tp_basicsize
+   sizeof(CppPyObject<PkgSrcRecordsStruct>),   // tp_basicsize
    0,                                   // tp_itemsize
    // Methods
-   CppOwnedDealloc<PkgSrcRecordsStruct>,   // tp_dealloc
+   CppDealloc<PkgSrcRecordsStruct>,   // tp_dealloc
    0,                                   // tp_print
    PkgSrcRecordsAttr,                      // tp_getattr
    0,                                   // tp_setattr

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--- End Message ---
--- Begin Message --- 
Fixed long, long ago. Closing.

Cheers,
Christian Aichinger

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