From 35aea3afcc6b6ec65a08f4db6ac06cf79e69ec55 Mon Sep 17 00:00:00 2001
From: "trop[bot]" <37223003+trop[bot]@users.noreply.github.com>
Date: Wed, 22 Apr 2026 12:32:47 +0200
Subject: [PATCH] fix: reset `printToPDF` queue after a rejection (#51221)
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fix: reset printToPDF queue after a rejection

The module-scoped `pendingPromise` in `webContents.printToPDF` was chained
with `.then(onFulfilled)` and never cleared. Once a call rejected (e.g.
an out-of-range `pageRanges` like `"999"`), subsequent calls chained onto
the rejected promise and short-circuited without ever invoking
`_printToPDF` — so every following call re-surfaced the original error.

Replace the shared variable with a per-`WebContents` `WeakMap` queue that
swallows prior rejections before chaining and clears its entry once the
tail drains.

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Shelley Vohr <shelley.vohr@gmail.com>
---
 lib/browser/api/web-contents.ts | 21 ++++++++++++---------
 spec/api-web-contents-spec.ts   | 10 ++++++++++
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/lib/browser/api/web-contents.ts b/lib/browser/api/web-contents.ts
index 5ebf6a4509..f067e30cba 100644
--- a/lib/browser/api/web-contents.ts
+++ b/lib/browser/api/web-contents.ts
@@ -212,7 +212,7 @@ function parsePageSize (pageSize: string | ElectronInternal.PageSize) {
 
 // Translate the options of printToPDF.
 
-let pendingPromise: Promise<any> | undefined;
+const printToPDFQueues = new WeakMap<Electron.WebContents, Promise<unknown>>();
 WebContents.prototype.printToPDF = async function (options) {
   const margins = checkType(options.margins ?? {}, 'object', 'margins');
   const pageSize = parsePageSize(options.pageSize ?? 'letter');
@@ -244,16 +244,19 @@ WebContents.prototype.printToPDF = async function (options) {
     ...pageSize
   };
 
-  if (this._printToPDF) {
-    if (pendingPromise) {
-      pendingPromise = pendingPromise.then(() => this._printToPDF(printSettings));
-    } else {
-      pendingPromise = this._printToPDF(printSettings);
-    }
-    return pendingPromise;
-  } else {
+  if (!this._printToPDF) {
     throw new Error('Printing feature is disabled');
   }
+
+  const prev = printToPDFQueues.get(this) ?? Promise.resolve();
+  const next = prev.catch(() => {}).then(() => this._printToPDF(printSettings));
+  printToPDFQueues.set(this, next);
+  next
+    .finally(() => {
+      if (printToPDFQueues.get(this) === next) printToPDFQueues.delete(this);
+    })
+    .catch(() => {});
+  return next;
 };
 
 // TODO(codebytere): deduplicate argument sanitization by moving rest of
diff --git a/spec/api-web-contents-spec.ts b/spec/api-web-contents-spec.ts
index 255e5dc424..3098541792 100644
--- a/spec/api-web-contents-spec.ts
+++ b/spec/api-web-contents-spec.ts
@@ -2996,6 +2996,16 @@ describe('webContents module', () => {
       expect(pdfInfo.numPages).to.equal(3);
     });
 
+    it('recovers after a prior call fails with an invalid page range', async () => {
+      await w.loadURL('data:text/html,<h1>Hello, World!</h1>');
+
+      await expect(w.webContents.printToPDF({ pageRanges: '999' })).to.eventually.be.rejected();
+
+      const data = await w.webContents.printToPDF({});
+      const pdfInfo = await readPDF(data);
+      expect(pdfInfo.numPages).to.equal(1);
+    });
+
     it('does not tag PDFs by default', async () => {
       await w.loadFile(path.join(__dirname, 'fixtures', 'api', 'print-to-pdf-small.html'));