Supports recording comment inner text in the resulting XDocument

Core.Tests/Parser/CommentTestFixture.cs

@@ -0,0 +1,57 @@
+using MonoDevelop.Xml.Analysis;
+using MonoDevelop.Xml.Dom;
+using MonoDevelop.Xml.Parser;
+using NUnit.Framework;
+
+namespace MonoDevelop.Xml.Tests.Parser
+{
+	[TestFixture]
+	public class CommentTestFixture
+	{
+		public virtual XmlRootState CreateRootState ()
+		{
+			return new XmlRootState ();
+		}
+
+		[TestCase ("<r><!-- text$ --></r>", " text ")]
+		[TestCase ("<r><!-- < $--></r>", " < ")]
+		[TestCase ("<r><!-- <! $--></r>", " <! ")]
+		[TestCase ("<r><!-- <!- $--></r>", " <!- ")]
+		public void Comment (string document, string innerText)
+		{
+			var parser = new XmlTreeParser (CreateRootState ());
+			var result = parser.Parse (document,
+				() => {
+					parser.AssertStateIs<XmlCommentState> ();
+				});
+
+			var comment = result.doc.RootElement?.FirstChild as XComment;
+
+			Assert.IsNotNull (comment);
+			Assert.AreEqual (innerText, comment.InnerText);
+		}
+
+		[TestCase ("<r><!-- ", 8)]
+		public void IncompleteCommentEof (string document, int startOffset)
+		{
+			var parser = new XmlTreeParser (CreateRootState ());
+			parser.Parse (document);
+
+			parser.AssertDiagnostics (
+				(XmlCoreDiagnostics.IncompleteCommentEof, startOffset, 0),
+				(XmlCoreDiagnostics.IncompleteTagEof, startOffset, 0)
+				);
+		}
+
+		[Test]
+		public void IncompleteEndCommentEof ()
+		{
+			var parser = new XmlTreeParser (CreateRootState ());
+			parser.Parse ("<r><!-- -- --></r>");
+
+			parser.AssertDiagnostics (
+				(XmlCoreDiagnostics.IncompleteEndComment, 10, 0)
+				);
+		}
+	}
+}

Core/Dom/XComment.cs

@@ -36,6 +36,17 @@ public XComment (TextSpan span) : base (span) {}
 		protected XComment () {}
 		protected override XObject NewInstance () { return new XComment (); }
 
+		public string InnerText { get; private set; } = "";
+
+		public void End (string text)
+		{
+			int startLen = "<!--".Length;
+			int endLen = "-->".Length;
+
+			InnerText = text;
+			Span = new TextSpan (Span.Start, startLen + text.Length + endLen);
+		}
+
 		public override string FriendlyPathRepresentation {
 			get { return "<!-- -->"; }
 		}

Core/Parser/XmlCommentState.cs

@@ -68,16 +68,19 @@ public class XmlCommentState : XmlParserState
 				}
 			} else {
 				// not any part of a '-->', so make sure matching is reset
+				if (context.StateTag == SINGLE_DASH)
+					context.KeywordBuilder.Append ('-');
+
 				context.StateTag = NOMATCH;
+				context.KeywordBuilder.Append (c);
 			}
 
 			return null;
 
 			XmlParserState? EndAndPop ()
 			{
 				var comment = (XComment)context.Nodes.Pop ();
-
-				comment.End (context.PositionAfterCurrentChar);
+				comment.End (context.KeywordBuilder.ToString());
 				if (context.BuildTree) {
 					((XContainer)context.Nodes.Peek ()).AddChildNode (comment);
 				}