Avoid the need for dependency loops

  * pure-Ruby library code is duplicated in native packages
  * if there is a ruby-foo-common package, the pure-Ruby libraries are
    installed in it instead.
  * programs are installed in either ruby-foo-common (if present), or in
    the first binary package otherwise.

lib/gem2deb/dhruby.rb

@@ -54,8 +54,6 @@ class DhRuby
     def initialize
       @verbose = true
       @bindir = '/usr/bin'
-      @prefix = nil
-      @libdir = '/usr/lib/ruby/vendor_ruby'
     end
 
     def clean
@@ -89,13 +87,13 @@ def test
     def install(argv)
       puts "Entering dh_ruby --install" if @verbose
 
+      packages_to_install_programs_in.each do |package|
+        install_files('bin', find_files('bin'), File.join(destdir_for(package), @bindir),             755) if File::directory?('bin')
+      end
 
-      # assume all Ruby files will be installed in the first package listed in
-      # debian/control, which should be ruby-foo OR foo
-      @prefix = destdir_for(packages.first)
-
-      install_files('bin', find_files('bin'), @bindir,          755) if File::directory?('bin')
-      install_files('lib', find_files('lib'), @libdir,  644) if File::directory?('lib')
+      packages_to_install_libraries_in.each do |package|
+        install_files('lib', find_files('lib'), File.join(destdir_for(package), libdir_for(package)), 644) if File::directory?('lib')
+      end
 
       packages.each do |package|
         # handle extensions
@@ -242,12 +240,12 @@ def find_files(dir, accept_pattern=nil)
     end
 
     def install_files(src, list, dest, mode)
-      run "install -d #{@prefix + '/' + dest}"
+      run "install -d #{dest}"
       list.each do |fname|
         if File::directory?(src + '/' + fname)
-          run "install -d #{@prefix + '/' + dest + '/' + fname}"
+          run "install -d #{dest + '/' + fname}"
         else
-          run "install -m#{mode} #{src + '/' + fname} #{@prefix + '/' + dest + '/' + fname}"
+          run "install -m#{mode} #{src + '/' + fname} #{dest + '/' + fname}"
         end
       end
     end
@@ -297,5 +295,57 @@ def atomic_rewrite(path, &block)
     def packages
       @packages ||= `dh_listpackages`.split
     end
+
+    def packages_to_install_libraries_in
+      if single_package?
+        packages
+      else
+        if has_common_package?
+          common_packages
+        else
+          native_packages
+        end
+      end
+    end
+
+    def packages_to_install_programs_in
+      if single_package?
+        packages
+      else
+        if has_common_package?
+          common_packages
+        else
+          packages.first
+        end
+      end
+    end
+
+    def single_package?
+      packages.size == 1
+    end
+
+    def has_common_package?
+      common_packages.size > 0
+    end
+
+    def common_packages
+      @common_packages ||= packages.grep /ruby-.*-common/
+    end
+
+    def native_packages
+      @native_packages ||= packages.select { |pkg| ruby_version_for(pkg) != 'ruby' }
+    end
+
+    def libdir_for(package)
+      case ruby_version_for(package)
+      when 'ruby1.8'
+        '/usr/lib/ruby/vendor_ruby/1.8'
+      when 'ruby1.9.1'
+        '/usr/lib/ruby/vendor_ruby/1.9.1'
+      else
+        '/usr/lib/ruby/vendor_ruby'
+      end
+    end
+
   end
 end

test/helper/samples.rb

@@ -18,5 +18,9 @@ module Samples
     SIMPLE_TGZ_NAME       = 'simpletgz'
     SIMPLE_TGZ_DIRNAME    = SIMPLE_TGZ_NAME + '-0.0.1'
     SIMPLE_TGZ            = File.join(SAMPLE_DIR, "#{SIMPLE_TGZ_NAME}/pkg/#{SIMPLE_TGZ_DIRNAME}.tgz")
+
+    SIMPLE_MIXED_NAME     = 'simplemixed'
+    SIMPLE_MIXED_DIRNAME  = SIMPLE_MIXED_NAME + '-1.2.3'
+    SIMPLE_MIXED          = File.join(SAMPLE_DIR, "#{SIMPLE_MIXED_NAME}/pkg/#{SIMPLE_MIXED_DIRNAME}.gem")
   end
 end

test/sample/simplemixed/Rakefile

@@ -0,0 +1,22 @@
+require 'rubygems'
+require 'rake/gempackagetask'
+
+spec = Gem::Specification.new do |s|
+  s.platform = Gem::Platform::RUBY
+  s.summary = "Simple native extension used to test dh_ruby"
+  s.name = 'simplemixed'
+  s.version = '1.2.3'
+  s.requirements << 'none'
+  s.require_path = 'ext'
+  s.extensions << 'ext/simplemixed/extconf.rb'
+  #s.autorequire = 'rake'
+  s.files = Dir.glob('{bin,ext,lib}/**/*')
+  s.description = <<EOF
+simplemixed is a simple mixed library (both pure-Ruby and native extension) that is used to test dh_ruby.
+EOF
+end
+
+Rake::GemPackageTask.new(spec) do |pkg|
+  pkg.need_zip = false
+  pkg.need_tar = false
+end

test/sample/simplemixed/bin/simplemixed

@@ -0,0 +1,3 @@
+#!/usr/bin/env ruby
+
+puts "I am a program installed by simplemixed"

test/sample/simplemixed/ext/simplemixed/extconf.rb

@@ -0,0 +1,2 @@
+require 'mkmf'
+create_makefile('simplemixed')

test/sample/simplemixed/ext/simplemixed/simplemixed.c

@@ -0,0 +1,5 @@
+#include "ruby.h"
+
+void Init_simplemixed() {
+  rb_define_module("SimpleMixed");
+}

test/sample/simplemixed/lib/simplemixed.rb

@@ -0,0 +1 @@
+require 'simplemixed.so'

test/unit/dh_ruby_test.rb

@@ -1,4 +1,6 @@
 require 'test_helper'
+require 'gem2deb/gem2tgz'
+require 'gem2deb/dh-make-ruby'
 require 'gem2deb/dhruby'
 require 'rbconfig'
 
@@ -8,6 +10,7 @@ class DhRubyTest < Gem2DebTestCase
     build(SIMPLE_GEM, SIMPLE_GEM_DIRNAME)
     build(SIMPLE_PROGRAM, SIMPLE_PROGRAM_DIRNAME)
     build(SIMPLE_EXTENSION, SIMPLE_EXTENSION_DIRNAME)
+    build(SIMPLE_MIXED, SIMPLE_MIXED_DIRNAME)
   end
 
   context 'installing simplegem' do
@@ -58,6 +61,56 @@ class DhRubyTest < Gem2DebTestCase
     end
   end
 
+  context 'mixed packages (both pure-Ruby and native library code)' do
+    should 'install Ruby libraries into single package' do
+      dh_ruby = Gem2Deb::DhRuby.new
+      dh_ruby.stubs(:packages).returns(['ruby-foo'])
+      assert_equal ['ruby-foo'], dh_ruby.send(:packages_to_install_libraries_in)
+    end
+
+    should 'install Ruby libraries in native packages' do
+      dh_ruby = Gem2Deb::DhRuby.new
+      dh_ruby.stubs(:packages).returns(['ruby-foo', 'ruby1.8-foo', 'ruby1.9.1-foo'])
+      assert_equal ['ruby1.8-foo', 'ruby1.9.1-foo'], dh_ruby.send(:packages_to_install_libraries_in)
+    end
+
+    should 'install Ruby code in ruby-foo-common package if it is present' do
+      dh_ruby = Gem2Deb::DhRuby.new
+      dh_ruby.stubs(:packages).returns(['ruby-foo', 'ruby1.8-foo', 'ruby1.9.1-foo', 'ruby-foo-common'])
+      assert_equal ['ruby-foo-common'], dh_ruby.send(:packages_to_install_libraries_in)
+    end
+
+    should 'install programs in single package' do
+      dh_ruby = Gem2Deb::DhRuby.new
+      dh_ruby.stubs(:packages).returns(['ruby-foo'])
+      assert_equal ['ruby-foo'], dh_ruby.send(:packages_to_install_programs_in)
+    end
+
+    should 'install programs in common package if present' do
+      dh_ruby = Gem2Deb::DhRuby.new
+      dh_ruby.stubs(:packages).returns(['ruby-foo', 'ruby1.8-foo', 'ruby1.9.1-foo', 'ruby-foo-common'])
+      assert_equal ['ruby-foo-common'], dh_ruby.send(:packages_to_install_programs_in)
+    end
+
+    should 'duplicate pure-Ruby code in native packages' do
+      assert_installed SIMPLE_MIXED_DIRNAME, 'ruby1.8-simplemixed', '/usr/lib/ruby/vendor_ruby/1.8/simplemixed.rb' 
+      assert_installed SIMPLE_MIXED_DIRNAME, 'ruby1.9.1-simplemixed', '/usr/lib/ruby/vendor_ruby/1.9.1/simplemixed.rb'
+    end
+
+  end
+
+  context 'calculating libdir for each package' do
+    {
+      'ruby-foo' => '/usr/lib/ruby/vendor_ruby',
+      'ruby1.8-foo' => '/usr/lib/ruby/vendor_ruby/1.8',
+      'ruby1.9.1-foo' => '/usr/lib/ruby/vendor_ruby/1.9.1',
+    }.each do |package,path|
+      should "install Ruby code for #{package} at #{path}" do
+        assert_equal path, Gem2Deb::DhRuby.new.send(:libdir_for, package)
+      end
+    end
+  end
+
   protected
 
   def assert_installed(gem_dirname, package, path)