From 276a5ab83b787ab3a615369aeeaea23496e3a424 Mon Sep 17 00:00:00 2001
From: Yorick Peterse <yorickpeterse@gmail.com>
Date: Mon, 25 Aug 2014 09:42:51 +0200
Subject: [PATCH] Support for lexing empty XPath strings.

---
 lib/oga/xpath/lexer.rl               |  4 ++--
 spec/oga/xpath/lexer/strings_spec.rb | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 spec/oga/xpath/lexer/strings_spec.rb

diff --git a/lib/oga/xpath/lexer.rl b/lib/oga/xpath/lexer.rl
index 640ccbf..5cdf58e 100644
--- a/lib/oga/xpath/lexer.rl
+++ b/lib/oga/xpath/lexer.rl
@@ -201,8 +201,8 @@ module Oga
         dquote = '"';
         squote = "'";
 
-        string_dquote = (dquote ^dquote+ dquote);
-        string_squote = (squote ^squote+ squote);
+        string_dquote = (dquote ^dquote* dquote);
+        string_squote = (squote ^squote* squote);
 
         string = string_dquote | string_squote;
 
diff --git a/spec/oga/xpath/lexer/strings_spec.rb b/spec/oga/xpath/lexer/strings_spec.rb
new file mode 100644
index 0000000..263fee6
--- /dev/null
+++ b/spec/oga/xpath/lexer/strings_spec.rb
@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe Oga::XPath::Lexer do
+  context 'strings' do
+    example 'lex a double quoted string' do
+      lex_xpath('"foo"').should == [[:T_STRING, 'foo']]
+    end
+
+    example 'lex a single quoted string' do
+      lex_xpath("'foo'").should == [[:T_STRING, 'foo']]
+    end
+
+    example 'lex an empty double quoted string' do
+      lex_xpath('""').should == [[:T_STRING, '']]
+    end
+
+    example 'lex an empty single quoted string' do
+      lex_xpath("''").should == [[:T_STRING, '']]
+    end
+  end
+end