This patch aborts the package installation and remove the package
from the database on any extraction error. This fixes FS#620.
I don't know why the extraction errors were ignored (even documented).
The initial commit already had this behaviour. Another odd thing
is that the install status of the package was commited to the database
before it was installed while there are exceptions used in pkg_install():
- archive open error
- empty archive
- archive read error
Any of these errors will falsely mark the package as installed (maybe
not a big problem with upgrades).
To avoid breaking something (else), this fix kicks in
only with fresh installs (not upgrades).
Thanks Erich Eckner, for pointing out that the issue
is reproductible with a read-only destination. Otherwise,
I don't think I would have looked at this issue.
A test case is presented with the FS issue, just in case someone
who loves C++ enough to dig deeper or have more knowledge about
the history of this program would take a closer look.
