[rubygems/rubygems] Move flock logic to its own method

https://github.com/rubygems/rubygems/commit/91274128a8

lib/rubygems.rb

@@ -791,23 +791,14 @@ An Array (#{env.inspect}) was passed in from #{caller[3]}
   end
 
   ##
-  # Open a file with given flags, and on Windows protect access with flock
+  # Open a file with given flags. It requires special logic on Windows, like
+  # protecting access with flock
 
   def self.open_file(path, flags, &block)
-    File.open(path, flags) do |io|
     if !java_platform? && win_platform?
-        begin
-          io.flock(File::LOCK_EX)
-        rescue Errno::ENOSYS, Errno::ENOTSUP
-        end
-      end
-      yield io
-    end
-  rescue Errno::ENOLCK # NFS
-    if Thread.main != Thread.current
-      raise
+      open_file_with_flock(path, flags, &block)
     else
-      File.open(path, flags, &block)
+      open_file_without_flock(path, flags, &block)
     end
   end
 
@@ -1307,6 +1298,26 @@ An Array (#{env.inspect}) was passed in from #{caller[3]}
 
     private
 
+    def open_file_with_flock(path, flags, &block)
+      File.open(path, flags) do |io|
+        begin
+          io.flock(File::LOCK_EX)
+        rescue Errno::ENOSYS, Errno::ENOTSUP
+        end
+        yield io
+      end
+    rescue Errno::ENOLCK # NFS
+      if Thread.main != Thread.current
+        raise
+      else
+        open_file_without_flock(path, flags, &block)
+      end
+    end
+
+    def open_file_without_flock(path, flags, &block)
+      File.open(path, flags, &block)
+    end
+
     def already_loaded?(file)
       $LOADED_FEATURES.any? do |feature_path|
         feature_path.end_with?(file) && default_gem_load_paths.any? {|load_path_entry| feature_path == "#{load_path_entry}/#{file}" }