From 050aaa40f8e690149c1f4c19999b17c54a66d4e8 Mon Sep 17 00:00:00 2001
From: Julian Rosse <julian@helixbass.net>
Date: Thu, 6 Apr 2017 19:39:13 -0400
Subject: [PATCH] Fix #4489: Regex octal escape sequence bug

---
 lib/coffee-script/lexer.js | 14 +++++++-------
 src/lexer.coffee           | 18 +++++++++++++++---
 test/error_messages.coffee |  7 +++++++
 3 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/lib/coffee-script/lexer.js b/lib/coffee-script/lexer.js
index c87dc96349..ef2737b4d8 100644
--- a/lib/coffee-script/lexer.js
+++ b/lib/coffee-script/lexer.js
@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 1.12.4
 (function() {
-  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVALID_ESCAPE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, ref, ref1, repeat, starts, throwSyntaxError,
+  var BOM, BOOL, CALLABLE, CODE, COFFEE_ALIASES, COFFEE_ALIAS_MAP, COFFEE_KEYWORDS, COMMENT, COMPARE, COMPOUND_ASSIGN, HERECOMMENT_ILLEGAL, HEREDOC_DOUBLE, HEREDOC_INDENT, HEREDOC_SINGLE, HEREGEX, HEREGEX_OMIT, HERE_JSTOKEN, IDENTIFIER, INDENTABLE_CLOSERS, INDEXABLE, INVERSES, JSTOKEN, JS_KEYWORDS, LEADING_BLANK_LINE, LINE_BREAK, LINE_CONTINUER, Lexer, MATH, MULTI_DENT, NOT_REGEX, NUMBER, OPERATOR, POSSIBLY_DIVISION, REGEX, REGEX_FLAGS, REGEX_ILLEGAL, REGEX_INVALID_ESCAPE, RELATION, RESERVED, Rewriter, SHIFT, SIMPLE_STRING_OMIT, STRICT_PROSCRIBED, STRING_DOUBLE, STRING_INVALID_ESCAPE, STRING_OMIT, STRING_SINGLE, STRING_START, TRAILING_BLANK_LINE, TRAILING_SPACES, UNARY, UNARY_MATH, VALID_FLAGS, WHITESPACE, compact, count, invertLiterate, isForFrom, isUnassignable, key, locationDataToString, ref, ref1, repeat, starts, throwSyntaxError,
     indexOf = [].indexOf || function(item) { for (var i = 0, l = this.length; i < l; i++) { if (i in this && this[i] === item) return i; } return -1; },
     slice = [].slice;
 
@@ -868,18 +868,16 @@
     };
 
     Lexer.prototype.validateEscapes = function(str, options) {
-      var before, hex, invalidEscape, match, message, octal, ref2, unicode;
+      var before, hex, invalidEscape, invalid_escape_regex, match, message, octal, ref2, unicode;
       if (options == null) {
         options = {};
       }
-      match = INVALID_ESCAPE.exec(str);
+      invalid_escape_regex = options.isRegex ? REGEX_INVALID_ESCAPE : STRING_INVALID_ESCAPE;
+      match = invalid_escape_regex.exec(str);
       if (!match) {
         return;
       }
       match[0], before = match[1], octal = match[2], hex = match[3], unicode = match[4];
-      if (options.isRegex && octal && octal.charAt(0) !== '0') {
-        return;
-      }
       message = octal ? "octal escape sequences are not allowed" : "invalid escape sequence";
       invalidEscape = "\\" + (octal || hex || unicode);
       return this.error(message + " " + invalidEscape, {
@@ -1067,7 +1065,9 @@
 
   LINE_CONTINUER = /^\s*(?:,|\??\.(?![.\d])|::)/;
 
-  INVALID_ESCAPE = /((?:^|[^\\])(?:\\\\)*)\\(?:(0[0-7]|[1-7])|(x(?![\da-fA-F]{2}).{0,2})|(u(?![\da-fA-F]{4}).{0,4}))/;
+  STRING_INVALID_ESCAPE = /((?:^|[^\\])(?:\\\\)*)\\(?:(0[0-7]|[1-7])|(x(?![\da-fA-F]{2}).{0,2})|(u(?![\da-fA-F]{4}).{0,4}))/;
+
+  REGEX_INVALID_ESCAPE = /((?:^|[^\\])(?:\\\\)*)\\(?:(0[0-7])|(x(?![\da-fA-F]{2}).{0,2})|(u(?![\da-fA-F]{4}).{0,4}))/;
 
   LEADING_BLANK_LINE = /^[^\n\S]*\n/;
 
diff --git a/src/lexer.coffee b/src/lexer.coffee
index df10eaa98b..7848c70661 100644
--- a/src/lexer.coffee
+++ b/src/lexer.coffee
@@ -763,10 +763,14 @@ exports.Lexer = class Lexer
 
   # Validates escapes in strings and regexes.
   validateEscapes: (str, options = {}) ->
-    match = INVALID_ESCAPE.exec str
+    invalid_escape_regex =
+      if options.isRegex
+        REGEX_INVALID_ESCAPE
+      else
+        STRING_INVALID_ESCAPE
+    match = invalid_escape_regex.exec str
     return unless match
     [[], before, octal, hex, unicode] = match
-    return if options.isRegex and octal and octal.charAt(0) isnt '0'
     message =
       if octal
         "octal escape sequences are not allowed"
@@ -978,7 +982,7 @@ HERECOMMENT_ILLEGAL = /\*\//
 
 LINE_CONTINUER      = /// ^ \s* (?: , | \??\.(?![.\d]) | :: ) ///
 
-INVALID_ESCAPE      = ///
+STRING_INVALID_ESCAPE = ///
   ( (?:^|[^\\]) (?:\\\\)* )        # make sure the escape isn’t escaped
   \\ (
      ?: (0[0-7]|[1-7])             # octal escape
@@ -986,6 +990,14 @@ INVALID_ESCAPE      = ///
       | (u(?![\da-fA-F]{4}).{0,4}) # unicode escape
   )
 ///
+REGEX_INVALID_ESCAPE = ///
+  ( (?:^|[^\\]) (?:\\\\)* )        # make sure the escape isn’t escaped
+  \\ (
+     ?: (0[0-7])                   # octal escape
+      | (x(?![\da-fA-F]{2}).{0,2}) # hex escape
+      | (u(?![\da-fA-F]{4}).{0,4}) # unicode escape
+  )
+///
 
 LEADING_BLANK_LINE  = /^[^\n\S]*\n/
 TRAILING_BLANK_LINE = /\n[^\n\S]*$/
diff --git a/test/error_messages.coffee b/test/error_messages.coffee
index e3a07e98c7..3e33db5e57 100644
--- a/test/error_messages.coffee
+++ b/test/error_messages.coffee
@@ -456,6 +456,13 @@ test "octal escapes", ->
     /a\\0\\tb\\\\\\07c/
       \  \   \ \ ^\^^
   '''
+  assertErrorFormat '''
+    /a\\1\\tb\\\\\\07c/
+  ''', '''
+    [stdin]:1:10: error: octal escape sequences are not allowed \\07
+    /a\\1\\tb\\\\\\07c/
+      \  \   \ \ ^\^^
+  '''
   assertErrorFormat '''
     ///a
       #{b} \\01///