fix: Add x: namespace prefix to sheetData elements for Excel compatib… by jogibear9988 · Pull Request #1 · dotnetprojects/EPPlusLGPL

jogibear9988 · 2025-12-02T14:26:55Z

…ility

Dynamically generated sheetData content was missing namespace prefixes, causing XML inconsistency when worksheet root uses 'x:' prefix.

Symptoms: Excel opens the file with correct file size but displays an empty worksheet - data is silently ignored due to malformed XML.

…ility Dynamically generated sheetData content was missing namespace prefixes, causing XML inconsistency when worksheet root uses 'x:' prefix. Symptoms: Excel opens the file with correct file size but displays an empty worksheet - data is silently ignored due to malformed XML.

Copilot

Pull request overview

This PR fixes XML namespace prefix inconsistency in dynamically generated Excel worksheet data. When the worksheet root element uses the 'x:' namespace prefix, all child elements within sheetData must also use this prefix to maintain XML validity.

Key Changes:

Added x: namespace prefix to dynamically generated sheetData, row, c (cell), f (formula), and v (value) elements
Commented out static CreateNode("d:sheetData") call since sheetData is now dynamically generated with the correct namespace
Updated both StringBuilder and StreamWriter-based WriteRow methods for consistency

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Copilot · 2025-12-02T14:30:52Z

                                if (f.IsArray)
                                {
-                                    cache.AppendFormat("<c r=\"{0}\" s=\"{1}\"{5}><f ref=\"{2}\" t=\"array\">{3}</f>{4}</c>", cse.CellAddress, styleID < 0 ? 0 : styleID, f.Address, ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));
+                                    cache.AppendFormat("<x:c r=\"{0}\" s=\"{1}\"{5}><x:f ref=\"{2}\" t=\"array\">{3}</x:f>{4}</x:c>", cse.CellAddress, styleID < 0 ? 0 : styleID, f.Address, ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));


The opening <f> tag is missing the x: namespace prefix while the closing tag has it (</x:f>). This creates an XML mismatch. Change <f ref= to <x:f ref= for consistency.

Copilot · 2025-12-02T14:30:52Z

                                else
                                {
-                                    cache.AppendFormat("<c r=\"{0}\" s=\"{1}\"{6}><f ref=\"{2}\" t=\"shared\" si=\"{3}\">{4}</f>{5}</c>", cse.CellAddress, styleID < 0 ? 0 : styleID, f.Address, sfId, ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));
+                                    cache.AppendFormat("<x:c r=\"{0}\" s=\"{1}\"{6}><x:f ref=\"{2}\" t=\"shared\" si=\"{3}\">{4}</x:f>{5}</x:c>", cse.CellAddress, styleID < 0 ? 0 : styleID, f.Address, sfId, ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));


The opening <f> tag is missing the x: namespace prefix while the closing tag has it (</x:f>). This creates an XML mismatch. Change <f ref= to <x:f ref= for consistency.

Copilot · 2025-12-02T14:30:52Z

                            else
                            {
-                                cache.AppendFormat("<c r=\"{0}\" s=\"{1}\"{4}><f t=\"shared\" si=\"{2}\"/>{3}</c>", cse.CellAddress, styleID < 0 ? 0 : styleID, sfId, GetFormulaValue(v), GetCellType(v, true));
+                                cache.AppendFormat("<x:c r=\"{0}\" s=\"{1}\"{4}><x:f t=\"shared\" si=\"{2}\"/>{3}</x:c>", cse.CellAddress, styleID < 0 ? 0 : styleID, sfId, GetFormulaValue(v), GetCellType(v, true));


The opening <f> tag is missing the x: namespace prefix. Change <f t= to <x:f t= for consistency with other formula elements.

Copilot · 2025-12-02T14:30:53Z

                            if (f.IsArray)
                            {
-                                cache.AppendFormat("<c r=\"{0}\" s=\"{1}\"{5}><f ref=\"{2}\" t=\"array\">{3}</f>{4}</c>", cse.CellAddress, styleID < 0 ? 0 : styleID, string.Format("{0}:{1}", f.Address, f.Address), ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));
+                                cache.AppendFormat("<x:c r=\"{0}\" s=\"{1}\"{5}><x:f ref=\"{2}\" t=\"array\">{3}</x:f>{4}</x:c>", cse.CellAddress, styleID < 0 ? 0 : styleID, string.Format("{0}:{1}", f.Address, f.Address), ConvertUtil.ExcelEscapeString(f.Formula), GetFormulaValue(v), GetCellType(v, true));


The opening <f> tag is missing the x: namespace prefix while the closing tag has it (</x:f>). This creates an XML mismatch. Change <f ref= to <x:f ref= for consistency.

Copilot

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 12 comments.

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Copilot · 2025-12-02T14:41:14Z

+            sw.Write("<x:mergeCells>");
            foreach (string address in _mergedCells)
            {
-                sw.Write("<mergeCell ref=\"{0}\" />", address);
+                sw.Write("<x:mergeCell ref=\"{0}\" />", address);
            }
-            sw.Write("</mergeCells>");
+            sw.Write("</x:mergeCells>");


The 'x:' namespace prefix is incorrect for main spreadsheet elements. The 'x:' prefix is registered for schemaMicrosoftExcel (urn:schemas-microsoft-com:office:excel) which is used for VML drawings, not for main spreadsheet elements like mergeCells, mergeCell, etc.

Main spreadsheet elements should either be:

Unprefixed (in the default namespace), OR

Match the prefix used in the original worksheet XML document

Hardcoding 'x:' prefix will break standard Excel files where these elements are unprefixed. Consider dynamically detecting and using the appropriate prefix from the worksheet root element instead of hardcoding 'x:'.

Copilot · 2025-12-02T14:41:14Z

            }
            else
            {   
                CreateNode("d:cols");


Commenting out CreateNode("d:sheetData") while adding 'x:' prefixes to dynamically generated sheetData content creates an inconsistency. If this line is commented out because sheetData will be dynamically generated, there should be an explanation comment. Additionally, this change coupled with the hardcoded 'x:' prefixes suggests a fundamental issue with namespace handling that needs a more comprehensive solution rather than piecemeal changes.

Suggested change

CreateNode("d:cols");

CreateNode("d:cols");

// The sheetData node is generated dynamically below, so we do not create it here.

// WARNING: Ensure that dynamically generated sheetData content uses consistent XML namespaces.

Copilot · 2025-12-02T14:41:15Z

            if (v != null && v.ToString()!="")
            {
-                return "<v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</v>"; //Fixes issue 15071
+                return "<x:v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</x:v>"; //Fixes issue 15071


The 'x:' namespace prefix is incorrect for the 'v' (value) element. This is a main spreadsheet schema element that should be unprefixed or match the worksheet's namespace prefix. Using 'x:' (which is for VML elements) will cause XML validation errors.

Suggested change

return "<x:v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</x:v>"; //Fixes issue 15071

return "<v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</v>"; //Fixes issue 15071

Copilot · 2025-12-02T14:41:15Z

+            if (prevRow != -1) sw.Write("</x:row>");
            //ulong rowID = ExcelRow.GetRowID(SheetID, row);
-            sw.Write("<row r=\"{0}\"", row);
+            sw.Write("<x:row r=\"{0}\"", row);


The 'x:' namespace prefix is incorrect for 'row' elements in the StreamWriter version. Row elements are part of the main spreadsheet schema and should either be unprefixed (default namespace) or match the prefix used in the original worksheet XML. The 'x:' prefix is reserved for VML drawing elements. This will break standard Excel files.

Copilot · 2025-12-02T14:41:16Z

+                    breaks.AppendFormat("<x:brk id=\"{0}\" max=\"16383\" man=\"1\"/>", cse.Column);
                    count++;
                }
            }
            if (count > 0)
            {
-                sw.Write(string.Format("<colBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</colBreaks>", count, breaks.ToString()));
+                sw.Write(string.Format("<x:colBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</x:colBreaks>", count, breaks.ToString()));


The 'x:' namespace prefix is incorrect for colBreaks and brk elements. These are main spreadsheet schema elements that should either be unprefixed (default namespace) or match the prefix used in the original worksheet XML. The 'x:' prefix is reserved for VML drawing elements (schemaMicrosoftExcel), not for these elements. This will cause XML validation errors and break compatibility with standard Excel files.

Copilot · 2025-12-02T14:41:16Z

+                    breaks.AppendFormat("<x:brk id=\"{0}\" max=\"1048575\" man=\"1\"/>", cse.Row);
                    count++;
                }
            }
            if (count>0)
            {
-                sw.Write(string.Format("<rowBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</rowBreaks>", count, breaks.ToString()));                
+                sw.Write(string.Format("<x:rowBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</x:rowBreaks>", count, breaks.ToString()));                


The 'x:' namespace prefix is incorrect for rowBreaks and brk elements. These are main spreadsheet schema elements that should either be unprefixed (default namespace) or match the prefix used in the original worksheet XML. The 'x:' prefix is reserved for VML drawing elements (schemaMicrosoftExcel), not for these elements. This will cause XML validation errors and break compatibility with standard Excel files.

Copilot · 2025-12-02T14:41:16Z

+            if (prevRow != -1) cache.Append("</x:row>");
            //ulong rowID = ExcelRow.GetRowID(SheetID, row);
-            cache.AppendFormat("<row r=\"{0}\"", row);
+            cache.AppendFormat("<x:row r=\"{0}\"", row);


The 'x:' namespace prefix is incorrect for 'row' elements. Row elements are part of the main spreadsheet schema and should either be unprefixed (default namespace) or match the prefix used in the original worksheet XML. The 'x:' prefix is reserved for VML drawing elements. This will break standard Excel files.

Copilot · 2025-12-02T14:41:16Z

            if (count > 0)
            {
-                sw.Write(string.Format("<colBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</colBreaks>", count, breaks.ToString()));
+                sw.Write(string.Format("<x:colBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</x:colBreaks>", count, breaks.ToString()));


Redundant call to 'ToString' on a String object.

Copilot · 2025-12-02T14:41:17Z

            if (count>0)
            {
-                sw.Write(string.Format("<rowBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</rowBreaks>", count, breaks.ToString()));                
+                sw.Write(string.Format("<x:rowBreaks count=\"{0}\" manualBreakCount=\"{0}\">{1}</x:rowBreaks>", count, breaks.ToString()));                


Redundant call to 'ToString' on a String object.

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Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

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When saving, inconsistent namespace prefixes were used, resulting in invalid XML documents. The prefix is now dynamically determined from the document and used consistently across all elements. - Extract _nsPrefix from WorksheetXml. DocumentElement - Replace all hardcoded "x:" prefixes with _nsPrefix - Add using alias RegexMatch to resolve naming conflict - Fix $"" combined with AppendFormat/string.Format calls

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

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                        {
                            id = hyps[hyp.OriginalString];
                        }
                        else
                        {
                            var relationship = Part.CreateRelationship(hyp, Packaging.TargetMode.External, ExcelPackage.schemaHyperlink);
                            if (uri is ExcelHyperLink)
                            {


 using OfficeOpenXml.Drawing;
 using OfficeOpenXml.Drawing.Chart;
 using OfficeOpenXml.Drawing.Vml;
 using OfficeOpenXml.FormulaParsing.LexicalAnalysis;


+        {
+            var worksheetNode = _worksheetXml.DocumentElement;
+            if (worksheetNode == null)
+            {
+                return string.Empty;
+            }
+
+            var prefix = worksheetNode.Prefix;
+            if (string.IsNullOrEmpty(prefix) && string.IsNullOrEmpty(worksheetNode.NamespaceURI) == false)
+            {
+                prefix = worksheetNode.GetPrefixOfNamespace(worksheetNode.NamespaceURI);
+            }
+
+            return string.IsNullOrEmpty(prefix) ? string.Empty : prefix + ":";
+        }
+


…lows (Shane32#29) Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Shane32 <6377684+Shane32@users.noreply.github.com> Co-authored-by: Shane Krueger <shane@acdmail.com>

Shane32#30) Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Shane32 <6377684+Shane32@users.noreply.github.com>

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Shane32 <6377684+Shane32@users.noreply.github.com>

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Copilot reviewed 13 out of 13 changed files in this pull request and generated 4 comments.

-                                sw.Write("<hyperlink ref=\"{0}\"{2}{3} r:id=\"{1}\"/>", ExcelCellBase.GetAddress(cse.Row, cse.Column), relationship.Id,                                
-                                    string.IsNullOrEmpty(hl.Display) ? "" : " display=\"" + SecurityElement.Escape(hl.Display) + "\"",
-                                    string.IsNullOrEmpty(hl.ToolTip) ? "" : " tooltip=\"" + SecurityElement.Escape(hl.ToolTip) + "\"");
+                                sw.Write($"<{_nsPrefix}hyperlink ref=\"{ExcelCellBase.GetAddress(cse.Row, cse.Column)}\"{(string.IsNullOrEmpty(hl.Display) ? "" : $" display=\"{SecurityElement.Escape(hl.Display)}\"")}{(string.IsNullOrEmpty(hl.ToolTip) ? "" : $" tooltip=\"{SecurityElement.Escape(hl.ToolTip)}\"")}" + $" r:id=\"{relationship.Id}\"/>");


+{
+  "sdk": {
+    "version": "8.0.100",
+    "rollForward": "latestFeature"
+  }
+}


          dotnet-version: |
            2.1.x
            3.1.x
            6.0.x
            8.0.x
+      - name: Setup .NET Core SDKs on Linux
+        if: matrix.os == 'ubuntu-latest'
+        uses: actions/setup-dotnet@v5
+        with:
+          dotnet-version: |
+            6.0.x
+            8.0.x


+
+steps:
+  - name: Setup .NET
+    uses: actions/setup-dotnet@v4


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Thomas Herrmann and others added 2 commits December 19, 2025 16:34

Refactor GetWorksheetNamespacePrefix

76e971c

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Shane32 added 3 commits May 5, 2026 22:09

Update EPPlus/ExcelWorksheet.cs

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Update EPPlus/ExcelWorksheet.cs

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Add GitHub Actions setup for .NET

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Fix SHFB documentation build failure on MSBuild 18.x (VS 2026 runners) (

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Merge branch 'master' into master

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Update empty sheetData node construction

b4ac302

	return "<x:v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</x:v>"; //Fixes issue 15071
	return "<v>" + ConvertUtil.ExcelEscapeString(GetValueForXml(v)) + "</v>"; //Fixes issue 15071

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