From ef9f25aa4d465c471a63bd2f1fd373591c02b809 Mon Sep 17 00:00:00 2001
From: Daria Ermakova <darya.ermakova@onlyoffice.com>
Date: Mon, 19 Jan 2026 16:04:31 +0300
Subject: [PATCH] Fix bug 75486

---
 MsBinaryFile/DocFile/DocumentMapping.cpp | 86 ++++++++++++++++++++----
 MsBinaryFile/DocFile/DocumentMapping.h   |  2 +-
 MsBinaryFile/DocFile/Plex.h              |  6 +-
 3 files changed, 78 insertions(+), 16 deletions(-)

diff --git a/MsBinaryFile/DocFile/DocumentMapping.cpp b/MsBinaryFile/DocFile/DocumentMapping.cpp
index d0f9dc6c61..8ea4aa5c8c 100644
--- a/MsBinaryFile/DocFile/DocumentMapping.cpp
+++ b/MsBinaryFile/DocFile/DocumentMapping.cpp
@@ -270,6 +270,7 @@ namespace DocFileFormat
 		int		cp							=	initialCp;
 		int		fc							=	m_document->FindFileCharPos(cp); 
 		int		fcEnd						=	m_document->FindFileCharPos(cpEnd);
+        bool    PBookmark                   = false;
 
 		ParagraphPropertyExceptions* papx	=	findValidPapx(fc);
 
@@ -406,13 +407,17 @@ namespace DocFileFormat
 						{
 							for (std::vector<std::vector<wchar_t> >::iterator iter = runs->begin(); iter != runs->end(); ++iter)
 							{
-								if (writeBookmarks(cp))
+                                if (writeBookmarks(cp, PBookmark))
 								{
 									cp = writeRun(&(*iter), chpxs->at(it), cp);
 								}
+                                PBookmark = true;
+                                if (cp == m_document->FIB->m_RgLw97.ccpText - 1)
+                                    writeBookmarks(cp, PBookmark);
 							}
 
 							RELEASEOBJECT(runs);
+                            PBookmark = false;
 						}
 					}
 					else
@@ -1971,22 +1976,77 @@ namespace DocFileFormat
 		}
 		return true;
 	}
-	bool DocumentMapping::writeBookmarks(int cp)
+    bool DocumentMapping::writeBookmarks(int cp, bool para)
 	{
 		bool result =	true;
+        static std::vector<int> openedInThisPara;
+        static std::set<int> allClosedIds;
+        static int nextIdForSequence = 0;
 
-		for (size_t b = 0; b < m_document->BookmarkStartEndCPs.size(); ++b)
-		{
-			if (m_document->BookmarkStartEndCPs[b].start == cp)
-			{
-				result = writeBookmarkStart(b);
-			}
+        for (size_t b = 0; b < m_document->BookmarkStartEndCPs.size(); ++b)
+        {
+            if (m_document->BookmarkStartEndCPs[b].start == cp)
+            {
+                int xmlId = b;
 
-			if (m_document->BookmarkStartEndCPs[b].end == cp)
-			{
-				result = writeBookmarkEnd(b);  
-			}
-		}
+                result = writeBookmarkStart(xmlId);
+                openedInThisPara.push_back(xmlId);
+            }
+        }
+
+        bool hasPositionClosings = false;
+        int positionClosingCount = 0;
+
+        for (size_t b = 0; b < m_document->BookmarkStartEndCPs.size(); ++b)
+        {
+            if (m_document->BookmarkStartEndCPs[b].end == cp)
+            {
+                hasPositionClosings = true;
+                positionClosingCount++;
+            }
+        }
+
+        if (hasPositionClosings)
+        {
+
+            for (int i = 0; i < positionClosingCount; i++)
+            {
+                if (!openedInThisPara.empty())
+                {
+                    int idToClose = openedInThisPara[0];
+                    result = writeBookmarkEnd(idToClose);
+                    allClosedIds.insert(idToClose);
+                    openedInThisPara.erase(openedInThisPara.begin());
+                }
+                else
+                {
+                    while (allClosedIds.find(nextIdForSequence) != allClosedIds.end())
+                    {
+                        nextIdForSequence++;
+                    }
+
+                    result = writeBookmarkEnd(nextIdForSequence);
+                    allClosedIds.insert(nextIdForSequence);
+                    nextIdForSequence++;
+                }
+            }
+        }
+        else if (para)
+        {
+            while (allClosedIds.find(nextIdForSequence) != allClosedIds.end())
+            {
+                nextIdForSequence++;
+            }
+
+            result = writeBookmarkEnd(nextIdForSequence);
+            allClosedIds.insert(nextIdForSequence);
+            nextIdForSequence++;
+        }
+
+        if (para)
+        {
+            openedInThisPara.clear();
+        }
 
 		return result;
 	}
diff --git a/MsBinaryFile/DocFile/DocumentMapping.h b/MsBinaryFile/DocFile/DocumentMapping.h
index 6678542dca..dc019d9072 100644
--- a/MsBinaryFile/DocFile/DocumentMapping.h
+++ b/MsBinaryFile/DocFile/DocumentMapping.h
@@ -118,7 +118,7 @@ namespace DocFileFormat
 		std::vector<int> searchAnnotation(std::vector<wchar_t>* chars, int initialCp);
 		std::vector<int> searchPermission(std::vector<wchar_t>* chars, int initialCp);
 
-		bool writeBookmarks		( int cp );
+        bool writeBookmarks		( int cp, bool para );
 		bool writeBookmarkStart	( short id );
 		bool writeBookmarkEnd	( short id );
 
diff --git a/MsBinaryFile/DocFile/Plex.h b/MsBinaryFile/DocFile/Plex.h
index 14a305b32f..a022b12d73 100644
--- a/MsBinaryFile/DocFile/Plex.h
+++ b/MsBinaryFile/DocFile/Plex.h
@@ -74,9 +74,11 @@ namespace DocFileFormat
                     {
                         n = totalSize / elementSize;
 
-                        if (totalSize % elementSize != 0)
+                        if (totalSize % elementSize != 0 && structureLength == 6)
                         {
-                            n += 1;
+                            structureLength = 4;
+                            elementSize = structureLength + CP_LENGTH;
+                            n = totalSize/elementSize;
                         }
                     }
 				}