Fix #45: guard drawing reconcile against undefined drawing entries

lib/xlsx/xlsx.js

@@ -97,7 +97,7 @@ class XLSX {
     Object.keys(model.drawings).forEach(name => {
       const drawing = model.drawings[name];
       const drawingRel = model.drawingRels[name];
-      if (drawingRel) {
+      if (drawing && drawingRel) {
         drawingOptions.rels = drawingRel.reduce((o, rel) => {
           o[rel.Id] = rel;
           return o;

spec/integration/issues/issue-45-drawing-without-anchors.spec.js

@@ -0,0 +1,105 @@
+'use strict';
+
+// Regression test for issue #45:
+// Drawings that produce no anchors (empty xdr:wsDr body) previously crashed
+// in the reconcile loop because drawing.anchors was undefined.  The fix
+// guards the reconcile block with `if (drawing && drawingRel)` and uses
+// `(drawing.anchors || [])` so both cases are safe.
+//
+// Note: the complementary case where DrawingXform.parseStream() itself returns
+// undefined (non-xdr:wsDr root) is covered by PR #70 and its test.  That
+// path requires the StreamBuf hang fix to be present; test it after #70 merges.
+
+const JSZip = require('jszip');
+const ExcelJS = verquire('exceljs');
+
+// Minimal XLSX parts -------------------------------------------------------
+
+const WORKBOOK_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+          xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
+  <sheets>
+    <sheet name="Sheet1" sheetId="1" r:id="rId1"/>
+  </sheets>
+</workbook>`;
+
+const WORKBOOK_RELS_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+  <Relationship Id="rId1"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"
+    Target="worksheets/sheet1.xml"/>
+</Relationships>`;
+
+const SHEET1_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+           xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
+  <sheetData>
+    <row r="1"><c r="A1" t="inlineStr"><is><t>Hello</t></is></c></row>
+  </sheetData>
+  <drawing r:id="rId1"/>
+</worksheet>`;
+
+const SHEET1_RELS_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+  <Relationship Id="rId1"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/drawing"
+    Target="../drawings/drawing1.xml"/>
+</Relationships>`;
+
+// A valid xdr:wsDr root but with NO anchor children — DrawingXform returns
+// {anchors: []} and reconcile must not crash on the empty anchors array.
+const DRAWING1_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<xdr:wsDr xmlns:xdr="http://schemas.openxmlformats.org/drawingml/2006/spreadsheetDrawing"
+          xmlns:a="http://schemas.openxmlformats.org/drawingml/2006/main">
+</xdr:wsDr>`;
+
+const DRAWING1_RELS_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+</Relationships>`;
+
+const CONTENT_TYPES_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
+  <Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/>
+  <Default Extension="xml" ContentType="application/xml"/>
+  <Override PartName="/xl/workbook.xml"
+    ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/>
+  <Override PartName="/xl/worksheets/sheet1.xml"
+    ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/>
+  <Override PartName="/xl/drawings/drawing1.xml"
+    ContentType="application/vnd.openxmlformats-officedocument.drawing+xml"/>
+</Types>`;
+
+const ROOT_RELS_XML = `<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+  <Relationship Id="rId1"
+    Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument"
+    Target="xl/workbook.xml"/>
+</Relationships>`;
+
+async function buildXlsxBuffer() {
+  const zip = new JSZip();
+  zip.file('[Content_Types].xml', CONTENT_TYPES_XML);
+  zip.file('_rels/.rels', ROOT_RELS_XML);
+  zip.file('xl/workbook.xml', WORKBOOK_XML);
+  zip.file('xl/_rels/workbook.xml.rels', WORKBOOK_RELS_XML);
+  zip.file('xl/worksheets/sheet1.xml', SHEET1_XML);
+  zip.file('xl/worksheets/_rels/sheet1.xml.rels', SHEET1_RELS_XML);
+  zip.file('xl/drawings/drawing1.xml', DRAWING1_XML);
+  zip.file('xl/drawings/_rels/drawing1.xml.rels', DRAWING1_RELS_XML);
+  return zip.generateAsync({type: 'nodebuffer'});
+}
+
+// --------------------------------------------------------------------------
+
+describe('github issue 45 - drawing reconcile does not crash on empty drawing', () => {
+  it('loads an XLSX with a drawing that has no anchors without throwing', async () => {
+    const buffer = await buildXlsxBuffer();
+    const wb = new ExcelJS.Workbook();
+    // Must not throw; before the fix `drawing.anchors` access could crash when
+    // the drawing model had no anchors array.
+    await wb.xlsx.load(buffer);
+    const ws = wb.getWorksheet('Sheet1');
+    expect(ws).to.exist;
+    expect(ws.getCell('A1').value).to.equal('Hello');
+  }).timeout(10000);
+});