From 7983cd067475fa4a417268919a09263a384c1887 Mon Sep 17 00:00:00 2001
From: morkt <muvluv.ru@gmail.com>
Date: Sat, 3 Dec 2016 19:18:59 +0400
Subject: [PATCH] moved BOM detection to separate methods.

---
 GUI/TextViewer.xaml.cs | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/GUI/TextViewer.xaml.cs b/GUI/TextViewer.xaml.cs
index 71d4f20c..e666cd14 100644
--- a/GUI/TextViewer.xaml.cs
+++ b/GUI/TextViewer.xaml.cs
@@ -114,29 +114,45 @@ namespace JustView
             var enc = Encoding.Default;
             if (3 == file.Read (m_test_buf, 0, 3))
             {
-                if (0xef == m_test_buf[0] && 0xbb == m_test_buf[1] && 0xbf == m_test_buf[2])
+                if (IsUTF8())
                     enc = Encoding.UTF8;
-                else if (0xfe == m_test_buf[0] && 0xff == m_test_buf[1])
+                else if (IsUTF16BE())
                     enc = Encoding.BigEndianUnicode;
-                else if (0xff == m_test_buf[0] && 0xfe == m_test_buf[1])
+                else if (IsUTF16LE())
                     enc = Encoding.Unicode;
             }
             file.Position = 0;
             return enc;
         }
 
+        private bool IsUTF8 ()
+        {
+            return 0xEF == m_test_buf[0] && 0xBB == m_test_buf[1] && 0xBF == m_test_buf[2];
+        }
+
+        private bool IsUTF16BE ()
+        {
+            return 0xFE == m_test_buf[0] && 0xFF == m_test_buf[1];
+        }
+
+        private bool IsUTF16LE ()
+        {
+            return 0xFF == m_test_buf[0] && 0xFE == m_test_buf[1];
+        }
+
         public bool IsTextFile (Stream file)
         {
             int read = file.Read (m_test_buf, 0, m_test_buf.Length);
             file.Position = 0;
+            if (read > 3 && (IsUTF8() || IsUTF16LE() || IsUTF16BE()))
+                return true;
             bool found_eol = false;
             for (int i = 0; i < read; ++i)
             {
                 byte c = m_test_buf[i];
                 if (c < 9 || (c > 0x0d && c < 0x1a) || (c > 0x1b && c < 0x20))
                     return false;
-                if (!found_eol && 0x0a == c)
-                    found_eol = true;
+                found_eol = found_eol || 0x0A == c;
             }
             return found_eol || read < 80;
         }