[rubygems/rubygems] Added only missing extensions option into pristine command

https://github.com/rubygems/rubygems/commit/cfd0e615d7

lib/rubygems/commands/pristine_command.rb

@@ -34,6 +34,12 @@ class Gem::Commands::PristineCommand < Gem::Command
       options[:extensions]     = value
     end
 
+    add_option("--only-missing-extensions",
+               "Only restore gems with missing extensions") do |value, options|
+      options[:extensions_set] = true
+      options[:only_missing_extensions] = value
+    end
+
     add_option("--only-executables",
                "Only restore executables") do |value, options|
       options[:only_executables] = value
@@ -107,6 +113,10 @@ extensions will be restored.
       Gem::Specification.select do |spec|
         spec.extensions && !spec.extensions.empty?
       end
+    elsif options[:only_missing_extensions]
+      Gem::Specification.select do |spec|
+        spec.missing_extensions?
+      end
     else
       get_all_gem_names.sort.map do |gem_name|
         Gem::Specification.find_all_by_name(gem_name, options[:version]).reverse

test/rubygems/test_gem_commands_pristine_command.rb

@@ -202,6 +202,54 @@ class TestGemCommandsPristineCommand < Gem::TestCase
     assert_empty out, out.inspect
   end
 
+  def test_execute_extensions_only_missing_extensions
+    a = util_spec "a" do |s|
+      s.extensions << "ext/a/extconf.rb"
+    end
+
+    ext_path = File.join @tempdir, "ext", "a", "extconf.rb"
+    write_file ext_path do |io|
+      io.write <<-'RUBY'
+      File.open "Makefile", "w" do |f|
+        f.puts "clean:\n\techo cleaned\n"
+        f.puts "all:\n\techo built\n"
+        f.puts "install:\n\techo installed\n"
+      end
+      RUBY
+    end
+
+    b = util_spec "b" do |s|
+      s.extensions << "ext/b/extconf.rb"
+    end
+
+    ext_path = File.join @tempdir, "ext", "b", "extconf.rb"
+    write_file ext_path do |io|
+      io.write <<-'RUBY'
+      File.open "Makefile", "w" do |f|
+        f.puts "clean:\n\techo cleaned\n"
+        f.puts "all:\n\techo built\n"
+        f.puts "install:\n\techo installed\n"
+      end
+      RUBY
+    end
+
+    install_gem a
+    install_gem b
+
+    # Remove the extension files for b
+    FileUtils.rm_rf b.gem_build_complete_path
+
+    @cmd.options[:only_missing_extensions] = true
+    @cmd.options[:args] = []
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    refute_includes @ui.output, "Restored #{a.full_name}"
+    assert_includes @ui.output, "Restored #{b.full_name}"
+  end
+
   def test_execute_no_extension
     a = util_spec "a" do |s|
       s.extensions << "ext/a/extconf.rb"