UTF-8 BOM handling

src/JSMin/EncodingDetector.php

@@ -0,0 +1,139 @@
+<?php
+
+namespace JSMin;
+
+/**
+ * @package JSMin
+ * @copyright 2015 Hans-Jürgen Tappe <hjtappe@users.noreply.github.com>
+ * @license http://opensource.org/licenses/mit-license.php MIT License
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * The Software shall be used for Good, not Evil.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+class EncodingDetector
+{
+    /**
+     * Default Target Encoding
+     */
+    const DEFAULT_ENCODING = 'UTF-8';
+
+    /**
+     * Debug output switch
+     */
+    const DEBUG = false;
+
+
+    /**
+     * Decode input file content to UTF-8, taking BOM into account.
+     *
+     * @param string $input Input string
+     * @throws EncodingException
+     */
+    public static function decode($input, $targetEncoding = NULL)
+    {
+        // Check for the target encoding.
+        if (is_null($targetEncoding)) {
+            $targetEncoding = self::get_encoding();
+        }
+
+        // Remove the utf-8 BOM to save transfer bytes.
+        // Otherwise, line breaks before the 2nd comment are kept and
+        // lots of zero bytes stay, leading to additional waste and
+        // parsing
+        // exceptions.
+        $first2 = substr($input, 0, 2);
+        $first3 = substr($input, 0, 3);
+        $first4 = substr($input, 0, 4);
+
+        // Unicode BOM is U+FEFF, but after encoded, it will look
+        // like this.
+        if ($first3 == chr(0xEF).chr(0xBB).chr(0xBF)) {
+            $encoding = 'UTF-8';
+            $input = substr($input, 3);
+        } elseif ($first4 == chr(0x00).chr(0x00).chr(0xFE).chr(0xFF)) {
+            $encoding = 'UTF-32BE';
+            $input = substr($input, 4);
+        } elseif ($first4 == chr(0xFF).chr(0xFE).chr(0x00).chr(0x00)) {
+            $encoding = 'UTF-32LE';
+            $input = substr($input, 4);
+        } elseif ($first2 == chr(0xFE).chr(0xFF)) {
+            $encoding = 'UTF-16BE';
+            $input = substr($input, 2);
+        } elseif ($first2 == chr(0xFF).chr(0xFE)) {
+            $encoding = 'UTF-16LE';
+            $input = substr($input, 2);
+        } else {
+            $encoding = 'UTF-8';
+            // No BOM
+        }
+
+        // Convert only convertible files.
+        if (strtoupper($encoding) != strtoupper($targetEncoding)) {
+            if (self::check_mbstring()) {
+                $input = mb_convert_encoding($input, $targetEncoding, $encoding);
+            } else {
+                $result = iconv(
+                        $in_charset = $encoding,
+                        $out_charset = $targetEncoding,
+                        $input);
+                if (false === $result)
+                {
+                    throw new EncodingException('Input string could not be converted.');
+                } else {
+                    $input = $result;
+                }
+            }
+        }
+
+        return $input;
+    }
+
+    /**
+     * Check the availability of mbstring.
+     * @returns boolean
+     */
+    private static function check_mbstring()
+    {
+        if (function_exists('mb_strlen') &&
+                ((int)ini_get('mbstring.func_overload') & 2)) {
+            self::DEBUG && error_log(__CLASS__.'::'.__FUNCTION__.': true');
+            return true;
+        } else {
+            self::DEBUG && error_log(__CLASS__.'::'.__FUNCTION__.': false');
+            return false;
+        }
+    }
+
+    /**
+     * Get the target encoding.
+     * @returns string 
+     */
+    private static function get_encoding()
+    {
+        $iniValue = ini_get('default_encoding');
+        if (!is_null($iniValue) && $iniValue != '') {
+            self::DEBUG && error_log(__CLASS__.'::'.__FUNCTION__.': '.$iniValue.' (INI VALUE)');
+            return $iniValue;
+        } else {
+            self::DEBUG && error_log(__CLASS__.'::'.__FUNCTION__.': '.self::DEFAULT_ENCODING.' (DEFAULT)');
+            return self::DEFAULT_ENCODING;
+        }
+    }
+}

src/JSMin/EncodingException.php

@@ -0,0 +1,6 @@
+<?php
+
+namespace JSMin;
+
+class EncodingException extends \Exception {
+}

src/JSMin/JSMin.php

@@ -111,9 +111,8 @@ public function min()
             mb_internal_encoding('8bit');
         }
 
-        if (isset($this->input[0]) && $this->input[0] === "\xef") {
-            $this->input = substr($this->input, 3);
-        }
+        // Encode the input string, taking the UTF-8 BOM into account
+        $this->input = EncodingDetector::decode($this->input);
 
         $this->input = str_replace("\r\n", "\n", $this->input);
         $this->inputLength = strlen($this->input);

tests/Resources/minify/expected/utf8-with-bom.js

@@ -0,0 +1,3 @@
+MyClass._A=new Array
+("One","Two","Three");MyClass._B=new Array
+("Ten","Twenty","Thirty");