Update the RbenvBundler#ensure_capable_ruby method so that it no long…

…er claims JRuby 1.9.x as capable when it's not (lack of Kernel.fork)

This should resolve issue #21.

README.md

@@ -56,6 +56,9 @@ to report Bundler-installed gem executables if available.
 
 **0.94** (July 21, 2012)
 
+* Fix issue [\#21](https://github.com/carsomyr/rbenv-bundler/issues/21), where
+  the `RbenvBundler#ensure_capable_ruby` method would claim JRuby 1.9.x as
+  capable when it's not (lack of `Kernel.fork`).
 * Fix issue [\#22](https://github.com/carsomyr/rbenv-bundler/issues/22). This
   addresses the corner cases when either the `manifest.txt` file doesn't exist
   or the `ruby_profiles.yml` file is first created.

etc/rbenv.d/bundler/rehash.rb

@@ -341,7 +341,8 @@ def self.build_ruby_profiles(out_dir = Pathname.new("."))
   #
   # @param [Hash] ruby_profile_map a Hash from rbenv version names to Ruby profiles.
   def self.ensure_capable_ruby(ruby_profile_map)
-    return nil if (SEMANTIC_RUBY_VERSION <=> [1, 9]) >= 0
+    # Check if the current Ruby is capable.
+    return nil if (SEMANTIC_RUBY_VERSION <=> [1, 9]) >= 0 && Gem.ruby_engine != "jruby"
 
     # Find all Rubies that are 1.9+ and are not JRuby (no Kernel.fork).
     rbenv_versions = ruby_profile_map.select do |rbenv_version, ruby_profile|