From 8fa5fcfe72855c0f79ef469f09fa8b2f84208130 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 26 Nov 2021 20:21:12 +0100
Subject: [PATCH] [Regression] Prevent errors, during loading, in the viewer
 for XFA-documents (PR 14295 follow-up)

In the second commit in PR 14295, I forgot that the pages in XFA-documents don't have references (like in regular PDF documents); sorry about that!
---
 web/pdf_link_service.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/web/pdf_link_service.js b/web/pdf_link_service.js
index 4286f2e3a..b5732ffe3 100644
--- a/web/pdf_link_service.js
+++ b/web/pdf_link_service.js
@@ -120,7 +120,7 @@ class PDFLinkService {
     if (typeof destRef === "object" && destRef !== null) {
       pageNumber = this._cachedPageNumber(destRef);
 
-      if (pageNumber === null) {
+      if (!pageNumber) {
         // Fetch the page reference if it's not yet available. This could
         // only occur during loading, before all pages have been resolved.
         this.pdfDocument
@@ -446,6 +446,9 @@ class PDFLinkService {
    * @private
    */
   _cachedPageNumber(pageRef) {
+    if (!pageRef) {
+      return null;
+    }
     const refStr =
       pageRef.gen === 0 ? `${pageRef.num}R` : `${pageRef.num}R${pageRef.gen}`;
     return this._pagesRefCache?.[refStr] || null;