Add spec.platform to .gemspec if on JRuby

[boris-petrov]

Thanks for merging the other pull-request!

Of course, it doesn't work simply like that, because of these:

phatworx/easy_captcha#30
rubygems/rubygems#1662 (comment)

I couldn't have caught this as this doesn't happen during development, only after a gem is released.

In short - this means that you have to build a Java specific version of the gem because the .gemspec file is evaluated only at gem-build-time. You're building it (I guess) with gem build dotdiff which builds it with a RUBY_PLATFORM which is not java and that's it - the gem will then require rmagick and not rmagick4j. I read in a bunch of places and the easiest way to "fix" this is to create a java-specific gem.

With this pull-request, doing a gem build dotdiff does what it did before (i.e. it outputs a dotdiff-2.0.1.gem file) but doing a jruby -S gem build dotdiff outputs a dotdiff-2.0.1-java.gem file. Unfortunately I'm unfamiliar with publishing gems so you'll have to test this - I'm not sure whether the gem also has to have a different name (something like: spec.name = "dotdiff" + (is_java ? '-java' : '')) or the fact that -java is automatically added to the version number is enough.

Thanks!

[boris-petrov]

@jnormington - ping. :)

[jnormington]

Sorry @boris-petrov I'll have a look at this today and see what I need to do - thanks for the ping

[jnormington]

@boris-petrov : Sorry for the delay, this should now be done when I installed the gem with jruby it correctly pulled the -java version. Thanks for your help getting this supported!

$ jruby -S gem install dotdiff
Fetching: rmagick4j-0.4.0-java.gem (100%)
Successfully installed rmagick4j-0.4.0-java
Fetching: dotdiff-2.0.3-java.gem (100%)
Successfully installed dotdiff-2.0.3-java
2 gems installed

same for MRI version it pulled the normal gem from rubygems. So you should be able to do the following

jruby -S gem install dotdiff and it just work.

Let me know if it doesn't