fix: excavate modules in canvas fallback

src/QRCodeCanvas.tsx

@@ -97,7 +97,7 @@ const QRCodeCanvas = React.forwardRef<HTMLCanvasElement, QRPropsCanvas>(
         if (isSupportPath2d) {
           ctx.fill(new Path2D(generatePath(cellsToDraw, margin)));
         } else {
-          cells.forEach((row, rdx) => {
+          cellsToDraw.forEach((row, rdx) => {
             row.forEach((cell, cdx) => {
               if (cell) {
                 ctx.fillRect(cdx + margin, rdx + margin, 1, 1);

tests/fallback.test.tsx

@@ -0,0 +1,46 @@
+import { render } from '@testing-library/react';
+import React from 'react';
+
+jest.mock('../src/utils', () => ({
+  ...jest.requireActual('../src/utils'),
+  isSupportPath2d: false,
+}));
+
+import { QRCodeCanvas } from '../src/QRCodeCanvas';
+
+describe('Canvas fallback rendering', () => {
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it('excavates modules behind an embedded image without Path2D', () => {
+    jest
+      .spyOn(HTMLImageElement.prototype, 'complete', 'get')
+      .mockReturnValue(true);
+    jest
+      .spyOn(HTMLImageElement.prototype, 'naturalHeight', 'get')
+      .mockReturnValue(128);
+    jest
+      .spyOn(HTMLImageElement.prototype, 'naturalWidth', 'get')
+      .mockReturnValue(128);
+    const fillRect = jest.spyOn(CanvasRenderingContext2D.prototype, 'fillRect');
+
+    render(
+      <QRCodeCanvas
+        value="https://ant.design"
+        imageSettings={{
+          src: 'logo.png',
+          width: 128,
+          height: 128,
+          x: 0,
+          y: 0,
+          excavate: true,
+        }}
+      />,
+    );
+
+    // The full-size image excavates the complete QR matrix, leaving only the
+    // background fill. Individual dark modules must not be painted beneath it.
+    expect(fillRect).toHaveBeenCalledTimes(1);
+  });
+});