From c47fcea6f9dca06875ee0edb649b81516ae18c5c Mon Sep 17 00:00:00 2001
From: Sergey Konovalov <Sergey.Konovalov@onlyoffice.com>
Date: Tue, 2 Dec 2025 19:17:29 +0300
Subject: [PATCH] [se] Check and update sharedStrings in initWithSharedStrings;
 Fix bug 78869

---
 cell/model/WorkbookElems.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/cell/model/WorkbookElems.js b/cell/model/WorkbookElems.js
index 1f55f2fbb0..206d807092 100644
--- a/cell/model/WorkbookElems.js
+++ b/cell/model/WorkbookElems.js
@@ -13058,9 +13058,21 @@ function RangeDataManagerElem(bbox, data)
 	};
 	/**
 	 * Initialize with sharedStrings from file. rely on uniqines
+	 * Adds new shared strings to existing ones without removing existing data
 	 * @param {Array<string | Array<{text: string, format: CellXfs}>>} sharedStrings
 	 */
 	CSharedStrings.prototype.initWithSharedStrings = function(sharedStrings) {
+		if (this.all.length > 0) {
+			for (let i = 0; i < sharedStrings.length; i++) {
+				const item = sharedStrings[i];
+				if (typeof item === 'string') {
+					this.addText(item);
+				} else {
+					this.addMultiText(item);
+				}
+			}
+			return;
+		}
 		this.all = sharedStrings.slice(); //copy
 		this.text = Object.create(null);
 		this.multiTextMap = Object.create(null);