From 8ff0f8e4dfe347251524b171b6cf184da242787d Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 27 Aug 2021 17:29:00 +0200
Subject: [PATCH 1/2] Use optional chaining even more in the `web/app.js` file

---
 web/app.js | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/web/app.js b/web/app.js
index f1c8fa003..5d12b6dda 100644
--- a/web/app.js
+++ b/web/app.js
@@ -853,12 +853,8 @@ const PDFViewerApplication = {
     this.pdfAttachmentViewer.reset();
     this.pdfLayerViewer.reset();
 
-    if (this.pdfHistory) {
-      this.pdfHistory.reset();
-    }
-    if (this.findBar) {
-      this.findBar.reset();
-    }
+    this.pdfHistory?.reset();
+    this.findBar?.reset();
     this.toolbar.reset();
     this.secondaryToolbar.reset();
 
@@ -1850,9 +1846,7 @@ const PDFViewerApplication = {
       this.printService.destroy();
       this.printService = null;
 
-      if (this.pdfDocument) {
-        this.pdfDocument.annotationStorage.resetModified();
-      }
+      this.pdfDocument?.annotationStorage.resetModified();
     }
     this.forceRendering();
   },
@@ -1864,10 +1858,7 @@ const PDFViewerApplication = {
   },
 
   requestPresentationMode() {
-    if (!this.pdfPresentationMode) {
-      return;
-    }
-    this.pdfPresentationMode.request();
+    this.pdfPresentationMode?.request();
   },
 
   triggerPrinting() {

From bc2bb18af7543f2aabb5ce311ed658b1da471cc2 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 27 Aug 2021 17:45:34 +0200
Subject: [PATCH 2/2] Simplify the `PDFViewerApplication.supportsFullscreen`
 getter

A lot of the code in this getter has existed ever since the initial PresentationMode-implementation was first added all the way back in PR 1938 (which is nine years ago now).
At this point in time however, there's now a simpler way detect if a browser supports the FullScreen API and we should thus be able to simplify this getter; please refer to https://developer.mozilla.org/en-US/docs/Web/API/Document/fullscreenEnabled#browser_compatibility
---
 web/app.js | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/web/app.js b/web/app.js
index 5d12b6dda..c2c6b7eae 100644
--- a/web/app.js
+++ b/web/app.js
@@ -679,21 +679,13 @@ const PDFViewerApplication = {
     if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
       return shadow(this, "supportsFullscreen", document.fullscreenEnabled);
     }
-    const doc = document.documentElement;
-    let support = !!(
-      doc.requestFullscreen ||
-      doc.mozRequestFullScreen ||
-      doc.webkitRequestFullScreen
+    return shadow(
+      this,
+      "supportsFullscreen",
+      document.fullscreenEnabled ||
+        document.mozFullScreenEnabled ||
+        document.webkitFullscreenEnabled
     );
-
-    if (
-      document.fullscreenEnabled === false ||
-      document.mozFullScreenEnabled === false ||
-      document.webkitFullscreenEnabled === false
-    ) {
-      support = false;
-    }
-    return shadow(this, "supportsFullscreen", support);
   },
 
   get supportsIntegratedFind() {