From dbd48ac5b44c7dcd699e206ce8310d655a3a19ee Mon Sep 17 00:00:00 2001
From: Wojciech Figat <wojtek@figat.pl>
Date: Wed, 3 Aug 2022 10:15:42 +0200
Subject: [PATCH] Fix parsing html tags with starting with slash

---
 Source/Engine/Utilities/HtmlParser.cs         | 40 +++++++++++++------
 .../Tools/FlaxEngine.Tests/TestHtmlParser.cs  | 19 +++++++++
 2 files changed, 46 insertions(+), 13 deletions(-)

diff --git a/Source/Engine/Utilities/HtmlParser.cs b/Source/Engine/Utilities/HtmlParser.cs
index 07296602d..b4ab1e24b 100644
--- a/Source/Engine/Utilities/HtmlParser.cs
+++ b/Source/Engine/Utilities/HtmlParser.cs
@@ -33,10 +33,20 @@ namespace FlaxEngine.Utilities
         /// </summary>
         public Dictionary<string, string> Attributes;
 
+        /// <summary>
+        /// True if this tag contained a leading forward slash (begin of the tag).
+        /// </summary>
+        public bool IsLeadingSlash;
+
         /// <summary>
         /// True if this tag contained a trailing forward slash (end of the tag).
         /// </summary>
-        public bool IsTrailingSlash;
+        public bool IsEndingSlash;
+
+        /// <summary>
+        /// True if this tag contained a leading or trailing forward slash.
+        /// </summary>
+        public bool IsSlash => IsLeadingSlash || IsEndingSlash;
     };
 
     /// <summary>
@@ -102,7 +112,6 @@ namespace FlaxEngine.Utilities
                 // Skip opening '<'
                 Move();
 
-                // Examine first tag character
                 char c = Peek();
                 if (c == '!' && Peek(1) == '-' && Peek(2) == '-')
                 {
@@ -112,15 +121,13 @@ namespace FlaxEngine.Utilities
                     NormalizePosition();
                     Move(endComment.Length);
                 }
-                else if (c == '/')
-                {
-                    // Skip over closing tags
-                    _pos = _html.IndexOf('>', _pos);
-                    NormalizePosition();
-                    Move();
-                }
                 else
                 {
+                    // Skip leading slash
+                    bool isLeadingSlash = c == '/';
+                    if (isLeadingSlash)
+                        Move();
+
                     // Parse tag
                     bool result = ParseTag(ref tag, name);
 
@@ -136,9 +143,16 @@ namespace FlaxEngine.Utilities
                             Move();
                     }
 
-                    // Return true if requested tag was found
                     if (result)
+                    {
+                        if (isLeadingSlash)
+                        {
+                            // Tag starts with '/'
+                            tag.StartPosition--;
+                            tag.IsLeadingSlash = true;
+                        }
                         return true;
+                    }
                 }
             }
 
@@ -188,7 +202,7 @@ namespace FlaxEngine.Utilities
                 {
                     // Handle trailing forward slash
                     if (requested)
-                        tag.IsTrailingSlash = true;
+                        tag.IsEndingSlash = true;
                     Move();
                     SkipWhitespace();
 
@@ -250,7 +264,7 @@ namespace FlaxEngine.Utilities
         private string ParseAttributeName()
         {
             int start = _pos;
-            while (!EOF && !char.IsWhiteSpace(Peek()) && Peek() != '>' && Peek() != '=')
+            while (!EOF && char.IsLetterOrDigit(Peek()))
                 Move();
             return _html.Substring(start, _pos - start);
         }
@@ -284,7 +298,7 @@ namespace FlaxEngine.Utilities
             {
                 // Parse unquoted value
                 start = _pos;
-                while (!EOF && !char.IsWhiteSpace(c) && c != '>')
+                while (!EOF && !char.IsWhiteSpace(c) && c != '>' && c != '/')
                 {
                     Move();
                     c = Peek();
diff --git a/Source/Tools/FlaxEngine.Tests/TestHtmlParser.cs b/Source/Tools/FlaxEngine.Tests/TestHtmlParser.cs
index e48c7e0a6..8ed81478a 100644
--- a/Source/Tools/FlaxEngine.Tests/TestHtmlParser.cs
+++ b/Source/Tools/FlaxEngine.Tests/TestHtmlParser.cs
@@ -68,8 +68,27 @@ namespace FlaxEngine.Tests
             return result;
         }
 
+        [TestCase("b<a>", ExpectedResult = false)]
+        [TestCase("b<a/>", ExpectedResult = true)]
+        [TestCase("b<a />", ExpectedResult = true)]
+        [TestCase("b<a  />", ExpectedResult = true)]
+        [TestCase("b<a size=50>", ExpectedResult = false)]
+        [TestCase("b<a size=50/>", ExpectedResult = true)]
+        [TestCase("b</a>", ExpectedResult = true)]
+        public bool TestEnding(string html)
+        {
+            var parser = new HtmlParser(html);
+            while (parser.ParseNext(out var tag))
+            {
+                return tag.IsSlash;
+            }
+            throw new System.Exception();
+        }
+
         [TestCase("b<a size=50>", ExpectedResult = 1)]
         [TestCase("sd b <a>", ExpectedResult = 5)]
+        [TestCase("sd b </a>", ExpectedResult = 5)]
+        [TestCase("sd b <a/>", ExpectedResult = 5)]
         public int TestStartPosition(string html)
         {
             var parser = new HtmlParser(html);