From 9d44a73ad0576de0145b08f2c707469bc4133176 Mon Sep 17 00:00:00 2001
From: Artem Pavlenko <artem@mapnik.org>
Date: Mon, 2 Jul 2018 15:07:41 +0200
Subject: [PATCH] fix - add single quoted string escaped chars support + allow
 backtracking when escaped characters are not part of /u, /U. /x encodings
 (ref
 https://github.com/mapnik/mapnik/commit/3433397c30461729183e1d1d0bc3a26dafba2875#commitcomment-29512684)

---
 include/mapnik/expression_grammar_x3_def.hpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/mapnik/expression_grammar_x3_def.hpp b/include/mapnik/expression_grammar_x3_def.hpp
index dd7d40eba..7f644f4c9 100644
--- a/include/mapnik/expression_grammar_x3_def.hpp
+++ b/include/mapnik/expression_grammar_x3_def.hpp
@@ -315,14 +315,14 @@ namespace mapnik { namespace grammar {
     auto const single_quoted_string = x3::rule<class single_quoted_string, std::string> {} = lit('\'')
         >> no_skip[*(unesc_char[append]
                      |
-                     //(lit('\\') > escaped_unicode[append]) // FIXME (!)
-                     //|
+                     (lit('\\') >> escaped_unicode[append])
+                     |
                      (~char_('\''))[append])] > lit('\'');
 
     auto const double_quoted_string = x3::rule<class double_quoted_string, std::string> {} = lit('"')
         >> no_skip[*(unesc_char[append]
                      |
-                     (lit('\\') > escaped_unicode[append])
+                     (lit('\\') >> escaped_unicode[append])
                      |
                      (~char_('"'))[append])] > lit('"');