Comment 11 for bug 1642386

And the results of git bisect, thanks for the excellent instruction and script!

cde5b485c9cdf0bfd5b6ea8e4973abe378270e60 is the first bad commit
commit cde5b485c9cdf0bfd5b6ea8e4973abe378270e60
Author: David Kalnischkies <email address hidden>
Date: Fri May 20 09:37:24 2016 +0200

    fail instead of segfault on unreadable config files

    The report mentions "apt list --upgradable", but there are others which
    have inconsistent behavior ranging from segfaulting to doing something
    with the partial (and hence incomplete) data. We had a recent report
    about sources.list (#818628), this one mentions prefences, the obvious
    next step is conf files… so the testcase is adapted to check for all
    three in file and directory versions and run a bunch of commands each
    time which should all have more or less the same behavior in such a case
    (aka error out).

    Closes: 824503
    (cherry picked from commit fdf9eef4d96a18d0167708499c993e1174251e88)

:040000 040000 04f4856e0a9313f9f51a5a6dc56c9af005ac54f4 98d34296e4f9212a124515095f6ed9afd5739111 M apt-pkg
:040000 040000 d48745d59ec9dd40087de492197c7a1060d1451d a5038f3b3730d8ba9e070f68a60af11fbe0e7ac3 M apt-private
:040000 040000 cfb7d9b7f8130e98173cf09a56eea0c232cc75fa c2f0ed862e98021705643c42a1b549306b648c15 M cmdline
:040000 040000 24d65ae746427999b728b85acb6969f509885cb1 82f28b27a48c3a6cf5b9caaf6434512a4a5dd79f M test
bisect run success