From 9f50b0af372bf41d70f1a6b5ce3c9b09d4facc79 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 2 Jan 2023 14:00:16 +0100
Subject: [PATCH 1/3] Enable the `defaultZoomDelay` option/preference
 unconditionally (PR 15812 follow-up)

This option/preference was disabled in GENERIC builds, see PR 15812, to avoid landing it *just before* a new release. Hence it should be fine to enable this now.
---
 web/app_options.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/web/app_options.js b/web/app_options.js
index 4d0a479d1..d0cafe242 100644
--- a/web/app_options.js
+++ b/web/app_options.js
@@ -70,8 +70,7 @@ const defaultOptions = {
   },
   defaultZoomDelay: {
     /** @type {number} */
-    value:
-      typeof PDFJSDev === "undefined" || !PDFJSDev.test("GENERIC") ? 400 : -1,
+    value: 400,
     kind: OptionKind.VIEWER + OptionKind.PREFERENCE,
   },
   defaultZoomValue: {

From 0860a5b16858775774019487ca29f42cac7f5f92 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 2 Jan 2023 14:05:33 +0100
Subject: [PATCH 2/3] Ensure that a document is loaded in
 `PDFViewer.{increaseScale, decreaseScale}` (PR 14053 follow-up)

This was always "wrong", since these methods (just like all the zoom-related ones) don't make sense unless there's an active document.
---
 web/pdf_viewer.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/web/pdf_viewer.js b/web/pdf_viewer.js
index fc54bc847..01544850e 100644
--- a/web/pdf_viewer.js
+++ b/web/pdf_viewer.js
@@ -2001,6 +2001,9 @@ class PDFViewer {
    * @param {Object|null} [options]
    */
   increaseScale(steps = 1, options = null) {
+    if (!this.pdfDocument) {
+      return;
+    }
     let newScale = this._currentScale;
     do {
       newScale = (newScale * DEFAULT_SCALE_DELTA).toFixed(2);
@@ -2019,6 +2022,9 @@ class PDFViewer {
    * @param {Object|null} [options]
    */
   decreaseScale(steps = 1, options = null) {
+    if (!this.pdfDocument) {
+      return;
+    }
     let newScale = this._currentScale;
     do {
       newScale = (newScale / DEFAULT_SCALE_DELTA).toFixed(2);

From 9089e75cce1ed4c3cc6e9d661096e4ee52141ba8 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 2 Jan 2023 14:10:36 +0100
Subject: [PATCH 3/3] Validate the options before adding the `ResizeObserver`
 in the `PDFViewer` constructor (PR 15830 follow-up)

In the GENERIC viewer, it doesn't make sense to register the `ResizeObserver` if the `container`/`viewer` options are not valid.
---
 web/pdf_viewer.js | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/web/pdf_viewer.js b/web/pdf_viewer.js
index 01544850e..788b78dd4 100644
--- a/web/pdf_viewer.js
+++ b/web/pdf_viewer.js
@@ -230,20 +230,13 @@ class PDFViewer {
       );
     }
     this.container = options.container;
-    this.#resizeObserver.observe(this.container);
-
     this.viewer = options.viewer || options.container.firstElementChild;
 
     if (
       typeof PDFJSDev === "undefined" ||
       PDFJSDev.test("!PRODUCTION || GENERIC")
     ) {
-      if (
-        !(
-          this.container?.tagName.toUpperCase() === "DIV" &&
-          this.viewer?.tagName.toUpperCase() === "DIV"
-        )
-      ) {
+      if (this.container?.tagName !== "DIV" || this.viewer?.tagName !== "DIV") {
         throw new Error("Invalid `container` and/or `viewer` option.");
       }
 
@@ -254,6 +247,8 @@ class PDFViewer {
         throw new Error("The `container` must be absolutely positioned.");
       }
     }
+    this.#resizeObserver.observe(this.container);
+
     this.eventBus = options.eventBus;
     this.linkService = options.linkService || new SimpleLinkService();
     this.downloadManager = options.downloadManager || null;