This is a related but possibly different problem.
If a user creates a tarball with 'tar -cf tarball.tar .' and then another
user extracts the tarball as root, then the current directory permissions
are changed.
The example file is firefox-57.0.source.tar.xz. Although the tarball
should not be extracted as user root, some users may do this. If it is
done in the /tmp directory, then the permissions change from 1777 to 0755
without any warning.
tar -tvf firefox-57.0.source.tar.xz
drwxr-xr-x 0/0 0 2017-11-12 08:58 ./
...
I have asked FF to update their script to skip the current directory, but
they have not thought it important enough to do so. At least not yet.
Is there any reason that tar should change the permissions or ownership of
the . directory if it is present in a tarball? Perhaps tar should not
allow this by default or even just ignore ./ completely if it is present.
-- Bruce Dubbs
linuxfromscratch.org
