From d31d51b66e3ce536d896f8c74c0736f995836678 Mon Sep 17 00:00:00 2001
From: Olivier Nizet <onizet@hotmail.com>
Date: Mon, 16 Sep 2024 22:51:25 +0200
Subject: [PATCH] Fix detecting reserved __GoBack bookmark and ensure it
 remains after the appended output

---
 src/Html2OpenXml/HtmlConverter.cs     |  3 ++-
 test/HtmlToOpenXml.Tests/BodyTests.cs | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/Html2OpenXml/HtmlConverter.cs b/src/Html2OpenXml/HtmlConverter.cs
index 5b64b31..a274eec 100755
--- a/src/Html2OpenXml/HtmlConverter.cs
+++ b/src/Html2OpenXml/HtmlConverter.cs
@@ -125,8 +125,9 @@ public async Task ParseHtml(string html, CancellationToken cancellationToken = d
             body.Append(para);
 
         // move the paragraph with BookmarkStart `_GoBack` as the last child
+        // That bookmark is continuously moved after the last edit
         var p = body.GetFirstChild<Paragraph>();
-        if (p != null && p.GetFirstChild<BookmarkStart>()?.Id == "_GoBack")
+        if (p != null && p.GetFirstChild<BookmarkStart>()?.Name == "_GoBack")
         {
             p.Remove();
             body.Append(p);
diff --git a/test/HtmlToOpenXml.Tests/BodyTests.cs b/test/HtmlToOpenXml.Tests/BodyTests.cs
index 2baeb46..187e2f2 100644
--- a/test/HtmlToOpenXml.Tests/BodyTests.cs
+++ b/test/HtmlToOpenXml.Tests/BodyTests.cs
@@ -55,5 +55,29 @@ public bool PageOrientation_OverrideExistingLayout_ReturnsLandscapeDimension(str
             var bidi = mainPart.Document.Body!.GetFirstChild<SectionProperties>()?.GetFirstChild<BiDi>();
             return bidi?.Val?.Value;
         }
+
+        [Test(Description = "Bookmark _GoBack is reserved and must stand after the last edit change")]
+        public async Task WithGoBackBookmark_ShouldBeAfterAppendedOutput()
+        {
+            using var generatedDocument = new MemoryStream();
+            using (var buffer = ResourceHelper.GetStream("Resources.DocWithCustomStyle.docx"))
+                buffer.CopyTo(generatedDocument);
+
+            generatedDocument.Position = 0L;
+            using WordprocessingDocument package = WordprocessingDocument.Open(generatedDocument, true);
+            MainDocumentPart mainPart = package.MainDocumentPart!;
+
+            var goBackBookmark = mainPart.Document.Body!.Elements<Paragraph>()
+                .FirstOrDefault(p => p.GetFirstChild<BookmarkStart>()?.Name?.Value == "_GoBack");
+            Assert.That(goBackBookmark, Is.Not.Null);
+
+            HtmlConverter converter = new HtmlConverter(mainPart);
+            await converter.ParseHtml("<p>Placeholder</p>");
+
+            Assert.That(mainPart.Document.Body!.LastChild, Is.TypeOf<SectionProperties>());
+            var paragrahs = mainPart.Document.Body!.Elements<Paragraph>();
+            Assert.That(paragrahs.Count(), Is.EqualTo(2));
+            Assert.That(paragrahs.Last().GetFirstChild<BookmarkStart>()?.Name?.Value, Is.EqualTo("_GoBack"));
+        }
     }
 }
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