From 8136c5f3dee9b791a0d4f4f63a1ba67e8181257a Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Fri, 14 May 2010 09:14:41 -0400
Subject: [PATCH] making regexes stricter about their flags.

---
 lib/lexer.js             | 13 +++++++++----
 src/lexer.coffee         |  5 +++--
 test/test_regexps.coffee | 10 +++++++++-
 3 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/lib/lexer.js b/lib/lexer.js
index fa39e5a1..dd207ea3 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -1,5 +1,5 @@
 (function(){
-  var ACCESSORS, ASSIGNMENT, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, CONVERSIONS, HALF_ASSIGNMENTS, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, LINE_BREAK, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX_ESCAPE, REGEX_FLAGS, REGEX_INTERPOLATION, REGEX_START, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, _a, _b, _c, balanced_string, compact, count, helpers, include, starts;
+  var ACCESSORS, ASSIGNMENT, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_KEYWORDS, COMMENT, COMMENT_CLEANER, CONVERSIONS, HALF_ASSIGNMENTS, HEREDOC, HEREDOC_INDENT, IDENTIFIER, INTERPOLATION, JS_CLEANER, JS_FORBIDDEN, JS_KEYWORDS, KEYWORDS, LAST_DENT, LAST_DENTS, LINE_BREAK, Lexer, MULTILINER, MULTI_DENT, NOT_REGEX, NO_NEWLINE, NUMBER, OPERATOR, REGEX_END, REGEX_ESCAPE, REGEX_INTERPOLATION, REGEX_START, RESERVED, Rewriter, STRING_NEWLINES, WHITESPACE, _a, _b, _c, balanced_string, compact, count, helpers, include, starts;
   var __slice = Array.prototype.slice;
   // The CoffeeScript Lexer. Uses a series of token-matching regexes to attempt
   // matches against the beginning of the source code. When a match is found,
@@ -239,7 +239,7 @@
     // JavaScript and Ruby, borrow slash balancing from `@balanced_token`, and
     // borrow interpolation from `@interpolate_string`.
     Lexer.prototype.regex_token = function regex_token() {
-      var flags, regex, str;
+      var end, flags, regex, str;
       if (!(this.chunk.match(REGEX_START))) {
         return false;
       }
@@ -249,7 +249,12 @@
       if (!(regex = this.balanced_token(['/', '/']))) {
         return false;
       }
-      regex += (flags = this.chunk.substr(regex.length).match(REGEX_FLAGS));
+      if (!(end = this.chunk.substr(regex.length).match(REGEX_END))) {
+        return false;
+      }
+      if (end[2]) {
+        regex += (flags = end[2]);
+      }
       if (regex.match(REGEX_INTERPOLATION)) {
         str = regex.substring(1).split('/')[0];
         str = str.replace(REGEX_ESCAPE, function(escaped) {
@@ -662,7 +667,7 @@
   // Regex-matching-regexes.
   REGEX_START = /^\/[^\/ ]/;
   REGEX_INTERPOLATION = /([^\\]\$[a-zA-Z_@]|[^\\]\$\{.*[^\\]\})/;
-  REGEX_FLAGS = /^[imgy]{0,4}/;
+  REGEX_END = /^(([imgy]{1,4})\b|\W)/;
   REGEX_ESCAPE = /\\[^\$]/g;
   // Token cleaning regexes.
   JS_CLEANER = /(^`|`$)/g;
diff --git a/src/lexer.coffee b/src/lexer.coffee
index e76ef1a7..286e269d 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -165,7 +165,8 @@ exports.Lexer: class Lexer
     return false unless @chunk.match REGEX_START
     return false if     include NOT_REGEX, @tag()
     return false unless regex: @balanced_token ['/', '/']
-    regex: + (flags: @chunk.substr(regex.length).match REGEX_FLAGS)
+    return false unless end: @chunk.substr(regex.length).match REGEX_END
+    regex: + flags: end[2] if end[2]
     if regex.match REGEX_INTERPOLATION
       str: regex.substring(1).split('/')[0]
       str: str.replace REGEX_ESCAPE, (escaped) -> '\\' + escaped
@@ -493,7 +494,7 @@ ASSIGNMENT    : /^(:|=)$/
 # Regex-matching-regexes.
 REGEX_START        : /^\/[^\/ ]/
 REGEX_INTERPOLATION: /([^\\]\$[a-zA-Z_@]|[^\\]\$\{.*[^\\]\})/
-REGEX_FLAGS        : /^[imgy]{0,4}/
+REGEX_END          : /^(([imgy]{1,4})\b|\W)/
 REGEX_ESCAPE       : /\\[^\$]/g
 
 # Token cleaning regexes.
diff --git a/test/test_regexps.coffee b/test/test_regexps.coffee
index 84cfe63c..2a57a418 100644
--- a/test/test_regexps.coffee
+++ b/test/test_regexps.coffee
@@ -12,4 +12,12 @@ g: 1
 
 ok y / x/g is 2
 
-ok 'http://google.com'.match(/:\/\/goog/)
\ No newline at end of file
+ok 'http://google.com'.match(/:\/\/goog/)
+
+obj: {
+  width:  -> 10
+  height: -> 20
+}
+id: 2
+
+ok (obj.width()/id - obj.height()/id) is -5