The previous version of these tests expected uuid_generate_v1() to always
emit MAC addresses with the local-admin and multicast address bits zero.
However, several of the buildfarm critters are reporting values with the
local-admin bit set. (Perhaps they're running inside VMs or jails.)
And a couple are reporting values with the multicast bit set, probably
meaning that the UUID library couldn't read the system MAC address.
Also, it emerges that if OSSP UUID can't read the system MAC address, it
falls back to V1MC behavior wherein the whole node field gets randomized
each time, breaking the test that expected the node field to remain stable
in V1 output. (It looks like e2fs doesn't behave that way, though.)
It's not entirely clear why we can't get a system MAC address, since the
buildfarm scripts would not work without internet access. Nonetheless,
the regression tests had better cope with the case, so adjust the tests
to expect these behaviors.
On reflection, the timestamp-advances test might fail if we're unlucky
enough for the time_mid field to change between two calls, since uuid_cmp
is just bytewise comparison and the field ordering has more significant
fields later. Build some field extraction functions so we can do a more
honest test of that. Also check that the version and reserved fields
contain what they should.
Allow the contrib/uuid-ossp extension to be built atop any one of these
three popular UUID libraries. (The extension's name is now arguably a
misnomer, but we'll keep it the same so as not to cause unnecessary
compatibility issues for users.)
We would not normally consider a change like this post-beta1, but the issue
has been forced by our upgrade to autoconf 2.69, whose more rigorous header
checks are causing OSSP's header files to be rejected on some platforms.
It's been foreseen for some time that we'd have to move away from depending
on OSSP UUID due to lack of upstream maintenance, so this is a down payment
on that problem.
While at it, add some simple regression tests, in hopes of catching any
major incompatibilities between the three implementations.
Matteo Beccati, with some further hacking by me
