Added dont_order_roots option

[smoyte]

From the proposed Readme text:

By default, root nodes are also assigned order values globally across the whole database table. So for instance if you have 5 nodes with no parent, they will be ordered 0 through 4 by default. If your model represents many separate trees and you have a lot of records, this can cause performance problems, and doesn't really make much sense.

This PR adds an option for disabling this behavior.

This was proposed in issue #282.

[smoyte]

Crap, will get those tests fixed and resubmit. Was working locally, hmm.

[smoyte]

Gosh, I'm having a real hard time replicating those two spec failures on my local machine. Here is what I tried (for the second one, on 2.3.6):

# Running with same settings as Travis:
rbenv install 2.3.6
rbenv local 2.3.6
export DB=postgresql
export BUNDLE_GEMFILE=$PWD/gemfiles/activerecord_5.2.gemfile
gem install bundler
bundle
bundle exec rake --trace spec:all

# Running one the failing specs a crap ton of times:
for run in {1..50}; do rspec spec/label_spec.rb:304; done

# Running the appropriate suite with the same random seed:
rspec --seed=29271

All the above produce nothing but green.

Any ideas?

[smoyte]

I ran the specs again last night and two jobs failed again, but they were different jobs!

So something intermittent is going on here. Still can't reproduce on my local.

I just added a bunch of debug outputs and am running the specs again on Travis.

[smoyte]

OK I think I found the issue -- I needed to call reload a few times in the test setup. Hopefully all should pass now...

[mceachen]

looks like the extra s is a typo

[smoyte]

How in the name of ...

I swear I ran this locally... anyway incoming...

[smoyte]

Yes!!!

[mceachen]

Nice!