[rubygems/rubygems] Refactor: Move filesystem access into Definition class

https://github.com/rubygems/rubygems/commit/2720da2659

lib/bundler/cli/lock.rb

@@ -64,7 +64,6 @@ module Bundler
           file = file ? File.expand_path(file) : Bundler.default_lockfile
           puts "Writing lockfile to #{file}"
           definition.lock(file)
-          FileUtils.touch(file)
         end
       end
 

lib/bundler/definition.rb

@@ -342,7 +342,10 @@ module Bundler
 
       preserve_unknown_sections ||= !updating_major && (Bundler.frozen_bundle? || !(unlocking? || @unlocking_bundler))
 
-      return if file && File.exist?(file) && lockfiles_equal?(@lockfile_contents, contents, preserve_unknown_sections)
+      if file && File.exist?(file) && lockfiles_equal?(@lockfile_contents, contents, preserve_unknown_sections)
+        FileUtils.touch(file)
+        return
+      end
 
       if Bundler.frozen_bundle?
         Bundler.ui.error "Cannot write a changed lockfile while frozen."