From 71b922b444fcf16d565c664e7e570699af545b66 Mon Sep 17 00:00:00 2001
From: Kouhei Sutou <kou@clear-code.com>
Date: Sun, 10 Aug 2014 21:21:03 +0900
Subject: [PATCH] Improve binary file detection

We can use `String#valid_encoding?` for detecting an undefined or invalid
character.
---
 lib/file_reverse_reader.rb | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/file_reverse_reader.rb b/lib/file_reverse_reader.rb
index a5f1312..ba95cba 100644
--- a/lib/file_reverse_reader.rb
+++ b/lib/file_reverse_reader.rb
@@ -36,8 +36,7 @@ class FileReverseReader
 
   def binary_file?
     sample = io.read(1024) || ""
-    sample2 = sample.force_encoding('ascii-8bit').encode('us-ascii', :undef => :replace, :invalid => :replace, :replace => "")
-    sample != sample2 # maybe binary file
+    !sample.force_encoding('us-ascii').valid_encoding?
   ensure
     io.rewind
   end