From 1c390a6c6264ab39e4921317dc8ac1d6ffee010b Mon Sep 17 00:00:00 2001
From: Artyom Baranovskiy <Artyom.Baranovskiy@gmail.com>
Date: Tue, 5 Nov 2013 23:04:35 +0300
Subject: [PATCH] Prevent Default OutputFormatter from breaking leading xml
 comment

- As some sites specify leading xml comment tag instead of doctype, xml
  comment tag should not be broken during parsing of any document
- When the comment tag is like <?...?> - simply render it's NodeValue as
  no more wrapping is required
---
 .../Core/OutputFormatters/FormatDefault.cs    | 22 +++++++++++++++++++
 source/CsQuery.Tests/Csquery.Tests.csproj     |  1 +
 .../CsQuery/Output/OutputFormatterDefault.cs  |  4 ++++
 3 files changed, 27 insertions(+)
 create mode 100644 source/CsQuery.Tests/Core/OutputFormatters/FormatDefault.cs

diff --git a/source/CsQuery.Tests/Core/OutputFormatters/FormatDefault.cs b/source/CsQuery.Tests/Core/OutputFormatters/FormatDefault.cs
new file mode 100644
index 00000000..384137df
--- /dev/null
+++ b/source/CsQuery.Tests/Core/OutputFormatters/FormatDefault.cs
@@ -0,0 +1,22 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using NUnit.Framework;
+using Assert = NUnit.Framework.Assert;
+
+namespace CsQuery.Tests.Core.OutputFormatters_
+{
+    [TestFixture, TestClass]
+    class FormatDefault
+    {
+        [Test, TestMethod]
+        public void RenderLeadingXmlTag()
+        {
+            const string XmlTag = @"<?xml version=""1.0"" encoding=""UTF-8""?>";
+
+            var formatter = new Output.FormatDefault();
+            var comment = new CsQuery.Implementation.DomComment(XmlTag);
+            var actual = formatter.Render(comment);
+
+            Assert.AreEqual(XmlTag, actual, "FormatDefault should not change leading xml tag.");
+        }
+    }
+}
diff --git a/source/CsQuery.Tests/Csquery.Tests.csproj b/source/CsQuery.Tests/Csquery.Tests.csproj
index 4e435cc8..66f300d0 100644
--- a/source/CsQuery.Tests/Csquery.Tests.csproj
+++ b/source/CsQuery.Tests/Csquery.Tests.csproj
@@ -96,6 +96,7 @@
     <Compile Include="Arrays.cs" />
     <Compile Include="AssertEx.cs" />
     <Compile Include="Core\Documents\MultipleDocs.cs" />
+    <Compile Include="Core\OutputFormatters\FormatDefault.cs" />
     <Compile Include="Core\Dom\DomContainer.cs" />
     <Compile Include="Core\Dom\InnerText.cs" />
     <Compile Include="Core\Dom\DomText.cs" />
diff --git a/source/CsQuery/Output/OutputFormatterDefault.cs b/source/CsQuery/Output/OutputFormatterDefault.cs
index b4cb1dc9..6c948817 100644
--- a/source/CsQuery/Output/OutputFormatterDefault.cs
+++ b/source/CsQuery/Output/OutputFormatterDefault.cs
@@ -430,6 +430,10 @@ protected void RenderCommentNode(IDomObject element, TextWriter writer)
             {
                 return;
             }
+            else if (element.NodeValue.StartsWith("<?") && element.NodeValue.EndsWith("?>"))
+            {
+                writer.Write(element.NodeValue);
+            }
             else
             {
                 writer.Write("<!--" + element.NodeValue + "-->");