Prevent Ruby 1.8 error with rescue clause

[ggilder]

In Ruby 1.8, the final line of the math_error_classes method would
return nil if Math::DomainError was not defined. That would cause the
rescue in distance_between_sphere to be effectively rescue *nil, which
produces "TypeError: class or module required for rescue clause".

[coveralls]

Coverage remained the same when pulling 6c74180 on ggilder:fix-ruby-18-error into 9446d23 on geokit:master.

[tamird]

👍 this causes sadness

[coveralls]

Coverage remained the same when pulling ac0f304 on ggilder:fix-ruby-18-error into 9446d23 on geokit:master.

[ggilder]

Travis build is failing to bundle on 1.8.7. I'm looking into it though I don't see how it can be related to this change...

[ggilder]

Actually, really confused how bundle can possibly be failing since the line in lib/ruby/site_ruby/1.8/rubygems/specification.rb calls compact before sort. How is a nil even getting through??

[ggilder]

It looks like Travis has been erroring on all the recent 1.8.7 builds (https://travis-ci.org/geokit/geokit/builds) so I think it's unrelated. It builds fine for me locally.

[mnoack]

Thank you @ggilder The ruby 1.8 errors are fixed in the latest rubygems release so that's fine.

2 things:

1. Could this be fixed by simply adding the line "error_classes"
2. More importantly what are some inputs (maybe you can help too @tamird) you used to get the error. I'm trying to write a test but it might take a while for me to get an error occurring, then I can write a test and have this code tested.

[ggilder]

Sure, adding error_classes at the end of the method would also work, tap just seems more idiomatic for Ruby IMO. As far as reproducing inputs for the error, I have seen the error in a production system but unfortunately our logging isn't showing me the exact lat/lng inputs triggering the bug. I'll try to track that down.

[mnoack]

@ggilder @tamird I've addressed the issues in 9c63ba8 Thanks for alerting me to the issue so it could be fixed.

[tamird]

@mnoack would you mind cutting a new release with this fix?

[mnoack]

No problem. Done 1.8.4 released