From 7bab8350c0d7c479234e1474d0681f52c599bd9d Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 21 Dec 2020 11:43:54 +0100
Subject: [PATCH] Avoid the `getJavaScript` API-call in
 `PDFViewerApplication._initializeAutoPrint` when "enableScripting" is set

Rather than calling `getJavaScript` in the API and then ignoring the result, when "enableScripting" is set, it should be more efficient/faster to simply skip it altogether instead.

Finally, the `setTimeout` call at the end of `PDFViewerApplication._initializeAutoPrint` is removed, since it doesn't seem necessary any more as far as I can tell.[1]
Note that when this functionality was originally added, back in PR 2839, it seems that `pagesPromise` simply waited for the `getPage` calls of *all* pages to resolve. Today, on the other hand, the viewer fetches *and* renders the first page *before* doing the remaining `getPage` calls, and only afterwards is `pagesPromise` resolved. Hence it's not really clear why we now need to delay printing even further with a `setTimeout` call.

---
[1] The patch was tested with the following documents: https://github.com/mozilla/pdf.js/blob/master/test/pdfs/bug1001080.pdf and https://github.com/mozilla/pdf.js/blob/master/test/pdfs/issue6106.pdf
---
 web/app.js | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/web/app.js b/web/app.js
index a57c8a5dfa456..c2ddd2b48d604 100644
--- a/web/app.js
+++ b/web/app.js
@@ -1652,7 +1652,7 @@ const PDFViewerApplication = {
   async _initializeAutoPrint(pdfDocument, openActionPromise) {
     const [openAction, javaScript] = await Promise.all([
       openActionPromise,
-      pdfDocument.getJavaScript(),
+      !AppOptions.get("enableScripting") ? pdfDocument.getJavaScript() : null,
     ]);
 
     if (pdfDocument !== this.pdfDocument) {
@@ -1660,10 +1660,10 @@ const PDFViewerApplication = {
     }
     let triggerAutoPrint = false;
 
-    if (openAction && openAction.action === "Print") {
+    if (openAction?.action === "Print") {
       triggerAutoPrint = true;
     }
-    if (javaScript && !AppOptions.get("enableScripting")) {
+    if (javaScript) {
       javaScript.some(js => {
         if (!js) {
           // Don't warn/fallback for empty JavaScript actions.
@@ -1686,9 +1686,7 @@ const PDFViewerApplication = {
     }
 
     if (triggerAutoPrint) {
-      setTimeout(() => {
-        this.triggerPrinting();
-      });
+      this.triggerPrinting();
     }
   },