fix: properly generate requestID in webContents.printToPDF() (#20769) (#20811)

lib/browser/api/web-contents.js

@@ -72,7 +72,6 @@ const defaultPrintingSetting = {
   headerFooterEnabled: false,
   marginsType: 0,
   isFirstRequest: false,
-  requestID: getNextId(),
   previewUIID: 0,
   previewModifiable: true,
   printToPDF: true,
@@ -240,7 +239,10 @@ WebContents.prototype.takeHeapSnapshot = function (filePath) {
 
 // Translate the options of printToPDF.
 WebContents.prototype.printToPDF = function (options) {
-  const printingSetting = Object.assign({}, defaultPrintingSetting)
+  const printingSetting = {
+    ...defaultPrintingSetting,
+    requestID: getNextId()
+  }
   if (options.landscape) {
     printingSetting.landscape = options.landscape
   }

spec/api-web-contents-spec.js

@@ -1279,6 +1279,25 @@ describe('webContents module', () => {
       assert.notStrictEqual(data.length, 0)
     })
 
+    it('does not crash when called multiple times', async () => {
+      w.destroy()
+      w = new BrowserWindow({
+        show: false,
+        webPreferences: {
+          sandbox: true
+        }
+      })
+      await w.loadURL('data:text/html,%3Ch1%3EHello%2C%20World!%3C%2Fh1%3E')
+      const promises = []
+      for (let i = 0; i < 2; i++) {
+        promises.push(w.webContents.printToPDF({}))
+      }
+      const results = await Promise.all(promises)
+      for (const data of results) {
+        expect(data).to.be.an.instanceof(Buffer).that.is.not.empty()
+      }
+    })
+
     // TODO(miniak): remove when promisification is complete
     it('can print to PDF (callback)', (done) => {
       w.destroy()