Extract fu_split_path and fu_relative_components_from

Author: nobu

lib/fileutils.rb

@@ -741,14 +741,10 @@ def ln_sr(src, dest, force: nil, noop: nil, verbose: nil)
     srcs = Array.try_convert(src) || [src]
     link = proc do |s, target_directory = true|
       s = File.path(s)
-      srcdirs = (File.realdirpath(s) rescue File.expand_path(s)).split(File::SEPARATOR)
-      destdirs = File.realdirpath(dest).split(File::SEPARATOR)
+      srcdirs = fu_split_path((File.realdirpath(s) rescue File.expand_path(s)))
+      destdirs = fu_split_path(File.realdirpath(dest))
       destdirs.pop unless target_directory
-      while srcdirs.first&.== destdirs.first
-        srcdirs.shift
-        destdirs.shift
-      end
-      s = File.join(Array.new(destdirs.size, '..'), srcdirs)
+      s = File.join(fu_relative_components_from(srcdirs, destdirs))
       d = target_directory ? File.join(dest, File.basename(s)) : dest
       fu_output_message "ln -s#{force ? 'f' : ''} #{s} #{d}" if verbose
       remove_file d, true if force
@@ -2495,6 +2491,20 @@ def fu_output_message(msg)   #:nodoc:
   end
   private_module_function :fu_output_message
 
+  def fu_split_path(path)
+    File.path(path).split(File::SEPARATOR)
+  end
+  private_module_function :fu_split_path
+
+  def fu_relative_components_from(target, base) #:nodoc:
+    i = 0
+    while target[i]&.== base[i]
+      i += 1
+    end
+    Array.new(base.size-i, '..').concat(target[i..-1])
+  end
+  private_module_function :fu_relative_components_from
+
   # This hash table holds command options.
   OPT_TABLE = {}    #:nodoc: internal use only
   (private_instance_methods & methods(false)).inject(OPT_TABLE) {|tbl, name|