[DRE-maint] Bug#783972: rubygems-integration: Incompatibility with ruby >= 2.1

[Gustavo Machado Campagnani Gama]

Package: rubygems-integration
Version: 1.8
Severity: minor

Dear Maintainer,

Starting with ruby 2.1, the rubygems package has split the Gem::Specification
class into three:

  Gem::BasicSpecification
  Gem::StubSpecification < Gem::BasicSpecification
  Gem::Specification < Gem::BasicSpecification

This is problematic when using rubygems-integration and ruby >= 2.1,
because the patch applied to the Gem::Specification class (in the file
/usr/lib/ruby/vendor_ruby/rubygems/defaults/operating_systems.rb) no
longer works on instances of the Gem::StubSpecification class. For me,
this issue manifests as the following warning that is printed by the
"spring" gem: 

Warning: Running `gem pristine --all` to regenerate your installed
gemspecs (and deleting then reinstalling your bundle if you use bundle
--path) will improve the startup performance of Spring.

And, naturally, running 'gem pristine --all' or reinstalling the bundle
doesn't really fix anything.

Below is a suggested patch to the "operating_systems.rb" file:

------------------------ CUT HERE ---------------------

end

-if RUBY_VERSION >= '2.0' then
-  class << Gem::Specification
+spec_class = if RUBY_VERSION >= '2.1'
+               Gem::BasicSpecification
+             elsif RUBY_VERSION >= '2.0'
+               Gem::Specification
+             else
+               nil
+             end
+if spec_class
+  class << spec_class

     alias :upstream_default_specifications_dir :default_specifications_dir
     def default_specifications_dir
------------------------ CUT HERE ---------------------


Thanks for your time and consideration.

-- 
Gustavo

-- System Information:
Debian Release: jessie/sid
  APT prefers trusty-security
  APT policy: (505, 'trusty-security'), (501, 'trusty-updates'), (500, 'trusty'), (400, 'trusty-proposed'), (400, 'trusty-backports')
Architecture: i386 (i686)

Kernel: Linux 3.16.0-31-generic (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

rubygems-integration depends on no packages.

rubygems-integration recommends no packages.

Versions of packages rubygems-integration suggests:
pn  bundler  <none>

-- no debconf information