Proper use of encoding for hashing international characters.

Gruntfile.js

@@ -50,6 +50,12 @@ module.exports = function(grunt) {
         },
         src: ['tmp/custom.txt']
       },
+      international_options: {
+        options: {
+          encoding: 'utf8'
+        },
+        src: ['tmp/international.txt']
+      },
     },
 
     // Unit tests.

tasks/rev.js

@@ -14,24 +14,25 @@ var fs = require('fs'),
 
 module.exports = function(grunt) {
 
-  function md5(filepath, algorithm, encoding) {
+  function md5(filepath, algorithm, encoding, fileEncoding) {
     var hash = crypto.createHash(algorithm);
     grunt.log.verbose.write('Hashing ' + filepath + '...');
-    hash.update(grunt.file.read(filepath));
+    hash.update(grunt.file.read(filepath), fileEncoding);
     return hash.digest(encoding);
   }
 
   grunt.registerMultiTask('rev', 'Prefix static asset file names with a content hash', function() {
 
     var options = this.options({
+      encoding: 'utf8',
       algorithm: 'md5',
       length: 8
     });
 
     this.files.forEach(function(filePair) {
       filePair.src.forEach(function(f) {
 
-        var hash = md5(f, options.algorithm, 'hex'),
+        var hash = md5(f, options.algorithm, 'hex', options.encoding),
           prefix = hash.slice(0, options.length),
           renamed = [prefix, path.basename(f)].join('.'),
           outPath = path.resolve(path.dirname(f), renamed);

test/fixtures/international.txt

@@ -0,0 +1 @@
+The quick brown fox jumps over the lazy dog åäöæøéßç

test/rev_test.js

@@ -43,4 +43,12 @@ exports.rev = {
 
     test.done();
   },
+  international_options: function(test) {
+    test.expect(1);
+
+    var exists = grunt.file.exists('tmp/faa07745.international.txt');
+    test.ok(exists, '8 character MD5 hash prefix for international content');
+
+    test.done();
+  }
 };