From 9c5c737cef67658def5512bf2f36771723efd50a Mon Sep 17 00:00:00 2001
From: Lucas Trzesniewski <lucas.trzesniewski@gmail.com>
Date: Sat, 25 Feb 2023 18:57:20 +0100
Subject: [PATCH] Prioritize longer keywords also when they're not alphanumeric

---
 .gitignore                                    |  3 ++
 .../XmlHighlightingDefinitionTests.cs         | 39 +++++++++++++++++++
 .../Xshd/XmlHighlightingDefinition.cs         |  4 +-
 3 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 ICSharpCode.AvalonEdit.Tests/Highlighting/XmlHighlightingDefinitionTests.cs

diff --git a/.gitignore b/.gitignore
index 86b4b6c0..c9f9de7e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,6 +45,9 @@ bld/
 # Visual Studio 2017 auto generated files
 Generated\ Files/
 
+# JetBrains Rider
+.idea/
+
 # MSTest test Results
 [Tt]est[Rr]esult*/
 [Bb]uild[Ll]og.*
diff --git a/ICSharpCode.AvalonEdit.Tests/Highlighting/XmlHighlightingDefinitionTests.cs b/ICSharpCode.AvalonEdit.Tests/Highlighting/XmlHighlightingDefinitionTests.cs
new file mode 100644
index 00000000..0bb05ef1
--- /dev/null
+++ b/ICSharpCode.AvalonEdit.Tests/Highlighting/XmlHighlightingDefinitionTests.cs
@@ -0,0 +1,39 @@
+using System.Linq;
+
+using ICSharpCode.AvalonEdit.Document;
+using ICSharpCode.AvalonEdit.Highlighting;
+using ICSharpCode.AvalonEdit.Highlighting.Xshd;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.AvalonEdit.Tests.Highlighting
+{
+	[TestFixture]
+	public class XmlHighlightingDefinitionTests
+	{
+		[Test]
+		public void LongerKeywordsArePreferred()
+		{
+			var color = new XshdColor { Name = "Result" };
+			var syntaxDefinition = new XshdSyntaxDefinition {
+				Elements = {
+					color,
+					new XshdRuleSet {
+						Elements = { new XshdKeywords {
+								ColorReference = new XshdReference<XshdColor>(null, color.Name),
+								Words = { "foo", "foo.bar." }
+							}
+						}
+					}
+				}
+			};
+
+			var document = new TextDocument("This is a foo.bar. keyword");
+			var highlighter = new DocumentHighlighter(document, new XmlHighlightingDefinition(syntaxDefinition, HighlightingManager.Instance));
+			var result = highlighter.HighlightLine(1);
+
+			var highlightedText = document.GetText(result.Sections.Single());
+			Assert.That(highlightedText, Is.EqualTo("foo.bar."));
+		}
+	}
+}
diff --git a/ICSharpCode.AvalonEdit/Highlighting/Xshd/XmlHighlightingDefinition.cs b/ICSharpCode.AvalonEdit/Highlighting/Xshd/XmlHighlightingDefinition.cs
index 1fd58063..5a493456 100644
--- a/ICSharpCode.AvalonEdit/Highlighting/Xshd/XmlHighlightingDefinition.cs
+++ b/ICSharpCode.AvalonEdit/Highlighting/Xshd/XmlHighlightingDefinition.cs
@@ -240,9 +240,9 @@ public object VisitKeywords(XshdKeywords keywords)
 					}
 					keyWordRegex.Append(@")\b");
 				} else {
-					keyWordRegex.Append('(');
+					keyWordRegex.Append("(?>");
 					int i = 0;
-					foreach (string keyword in keywords.Words) {
+					foreach (string keyword in keywords.Words.OrderByDescending(w => w.Length)) {
 						if (i++ > 0)
 							keyWordRegex.Append('|');
 						if (char.IsLetterOrDigit(keyword[0]))