svg cannot have have filename 'length'

Gruntfile.js

@@ -348,6 +348,16 @@ module.exports = function(grunt) {
 					stylesheets: ['css', 'scss', 'less']
 				}
 			},
+			filename_length: {
+				src: 'test/src_filename_length/*.svg',
+				dest: 'test/tmp/filename_length',
+				options: {
+					autoHint: false,
+					engine: 'node',
+					hashes: false,
+					types: 'woff'
+				}
+			},
 		},
 		nodeunit: {
 			all: ['test/webfont_test.js']

tasks/webfont.js

@@ -622,7 +622,7 @@ module.exports = function(grunt) {
 		 * @return {Integer}
 		 */
 		function getNextCodepoint() {
-			while (_.includes(o.codepoints, currentCodepoint)) {
+			while (_.invert(o.codepoints).hasOwnProperty(currentCodepoint)) {
 				currentCodepoint++;
 			}
 			return currentCodepoint;

test/webfont_test.js

@@ -915,6 +915,20 @@ exports.webfont = {
 		// Files should render with custom context variables
 		test.ok(fs.existsSync('test/tmp/custom_output/context-test.html'));
 
+		test.done();
+	},
+
+	filename_length: function(test) {
+
+		// File should have been created.
+		test.ok(fs.existsSync('test/tmp/filename_length/icons.css'));
+
+		// File should have been created.
+		test.ok(fs.existsSync('test/tmp/filename_length/icons.woff'));
+
+		// File should have been created.
+		test.ok(fs.existsSync('test/tmp/filename_length/icons.html'));
+
 		test.done();
 	}