Leave back-references intact

This fixes an issue that was caused by an upstream bug in regjsparser.

Closes #4.

README.md

@@ -55,7 +55,8 @@ console.log([
 ## Known limitations
 
 1. _regexpu_ only transpiles regular expression _literals_, so things like `RegExp('…', 'u')` are not affected.
-2. It doesn’t polyfill [the `RegExp.prototype.unicode` getter](https://mths.be/es6#sec-get-regexp.prototype.unicode) because it’s not possible to do so without side effects.
+2. _regexpu_ doesn’t polyfill [the `RegExp.prototype.unicode` getter](https://mths.be/es6#sec-get-regexp.prototype.unicode) because it’s not possible to do so without side effects.
+3. _regexpu_ doesn’t support [canonicalizing the contents of back-references in regular expressions with both the `i` and `u` flag set](https://github.com/mathiasbynens/regexpu/issues/4), since that would require transpiling/wrapping strings.
 
 ## Installation
 

package.json

@@ -56,8 +56,8 @@
 		"esprima": "git+https://github.com/mathiasbynens/esprima-es6-regexp.git",
 		"recast": "^0.7.0",
 		"regenerate": "^0.6.4",
-		"regjsgen": "^0.1.2",
-		"regjsparser": "^0.1.0"
+		"regjsgen": "^0.2.0",
+		"regjsparser": "^0.1.2"
 	},
 	"devDependencies": {
 		"coveralls": "^2.11.1",

src/rewrite-pattern.js

@@ -169,7 +169,7 @@ function processTerm(item) {
 		case 'anchor':
 		case 'empty':
 		case 'group':
-		case 'ref':
+		case 'reference':
 			// Nothing to do here.
 			break;
 		// The `default` clause is only here as a safeguard; it should never be

tests/tests.js

@@ -214,6 +214,11 @@ var fixtures = [
 		'pattern': '\uD834\uDF06{2,4}',
 		'flags': FLAGS_WITH_UNICODE,
 		'transpiled': '(?:\\uD834\\uDF06){2,4}'
+	},
+	{
+		'pattern': '(a)\\1',
+		'flags': FLAGS_WITH_UNICODE_WITHOUT_I,
+		'transpiled': '(a)\\1'
 	}
 ];