commit-email.rb: Use base64 instead of nkf

which makes it more obvious what it's doing.

Author: k0kubun

tool/commit-email.rb

@@ -1,7 +1,7 @@
 #!/usr/bin/env ruby
 
 require "optparse"
-require "nkf"
+require "base64"
 require "shellwords"
 
 CommitEmailInfo = Struct.new(
@@ -207,7 +207,8 @@ def sendmail(to, from, mail)
   private
 
   def b_encode(str)
-    NKF.nkf('-WwM', str)
+    base64_str = Base64.encode64(str.force_encoding('UTF-8')).strip # NKF.nkf('-WwMB', str)
+    "=?UTF-8?B?#{base64_str}?="
   end
 
   def make_body(info, viewer_uri:)
@@ -351,7 +352,7 @@ def make_from(name:, email:)
       escaped_name = name.gsub(/["\\\n]/) { |c| "\\#{c}" }
       %Q["#{escaped_name}" <#{email}>]
     else
-      escaped_name = "=?UTF-8?B?#{NKF.nkf('-WwMB', name)}?="
+      escaped_name = b_encode(name)
       %Q[#{escaped_name} <#{email}>]
     end
   end

tool/test/test_commit_email.rb

@@ -30,7 +30,7 @@ def setup
   # Just testing an exit status :p
   # TODO: prepare something in test/fixtures/xxx and test output
   def test_successful_run
-    _, err, status = EnvUtil.invoke_ruby([gem_env, '-e', 'require "nkf"'], '', false, true)
+    _, err, status = EnvUtil.invoke_ruby([gem_env, '-e', 'require "base64"'], '', false, true)
     unless status.success?
       omit "bundled gems are not available: #{err}"
     end