Globbed jar contents with expand path failing in RubyGems

[headius]

In #5996 we discovered that a RubyGems update seems to break our ability to use a jar file as a GEM_PATH.

The failures look like this:

TestJarredGemsWithSpacesInDirectory: 
  test_jarred_gem_on_gem_path:					E
================================================================================
org/jruby/RubyKernel.java:1187:in `catch'
org/jruby/RubyKernel.java:1192:in `catch'
org/jruby/RubyKernel.java:1187:in `catch'
org/jruby/RubyKernel.java:1192:in `catch'
     26:     Gem.clear_paths
     27:     old = ENV['GEM_PATH']
     28:     ENV['GEM_PATH'] = File.expand_path('../gem.jar', __FILE__)
  => 29:     assert require('mygem')
     30:   ensure
     31:     ENV['GEM_PATH'] = old
     32:     Gem.clear_paths
/home/travis/build/jruby/jruby/test/jruby/test_jarred_gems.rb:29:in `test_jarred_gem_on_gem_path'
/home/travis/build/jruby/jruby/lib/ruby/stdlib/rubygems/core_ext/kernel_require.rb:54:in `require'
org/jruby/RubyKernel.java:977:in `require'
Error: test_jarred_gem_on_gem_path(TestJarredGemsWithSpacesInDirectory): LoadError: no such file to load -- mygem
================================================================================
: (0.018789)
  test_list_gem_from_jar_with_spaces_in_directory:		F
================================================================================
org/jruby/RubyKernel.java:1187:in `catch'
org/jruby/RubyKernel.java:1192:in `catch'
org/jruby/RubyKernel.java:1187:in `catch'
org/jruby/RubyKernel.java:1192:in `catch'
      6: 
      7:   def test_list_gem_from_jar_with_spaces_in_directory
      8:     out = jruby(%q{-r"./test/jruby/dir with spaces/testgem.jar" -S jgem list})
  =>  9:     assert(out =~ /testgem/)
     10: 
     11:     cp = ENV['CLASSPATH']
     12:     begin
/home/travis/build/jruby/jruby/test/jruby/test_jarred_gems.rb:9:in `test_list_gem_from_jar_with_spaces_in_directory'
Failure: test_list_gem_from_jar_with_spaces_in_directory(TestJarredGemsWithSpacesInDirectory): <nil> is not true.
================================================================================

These failures are due to a change in rubygems/rubygems@28c1f22 that modifies how gem paths are globbed to find gems and gemspecs.

The failure happens when doing one of two things and then trying to load a jarred gem:

• Requiring a jar that contains a "GEM_PATH" style layout
• Setting GEM_PATH to a jar that contains the appropriate layout

In each case, the "2.5" section in util.rb is the cause, and disabling that branch makes the jarred gem work correctly again.

A reduced script demonstrating the problem outside of RubyGems is here (using the test/jruby/gem.jar file in our repository:

glob = "*.gemspec"
base_path = "file:/Users/headius/projects/jruby/test/jruby/gem.jar!/specifications"

p Dir.glob(glob, base: base_path).map! {|f| File.expand_path(f, base_path) }
p Dir.glob(File.expand_path(glob, base_path))

The first glob is the one that fails, producing an empty array.