From 76f23ce3b5afa2e978c3d90306020d2405a7d27c Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 17 Apr 2025 13:57:30 +0200
Subject: [PATCH 1/2] Catch, and ignore, errors during
 `Page.prototype.getStructTree`

This way any errors thrown during parsing of the page-structTree will not be forwarded to the viewer.
---
 src/core/document.js | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/core/document.js b/src/core/document.js
index b1e1caaec..7324c9980 100644
--- a/src/core/document.js
+++ b/src/core/document.js
@@ -707,10 +707,18 @@ class Page {
     // Ensure that the structTree will contain the page's annotations.
     await this._parsedAnnotations;
 
-    const structTree = await this.pdfManager.ensure(this, "_parseStructTree", [
-      structTreeRoot,
-    ]);
-    return this.pdfManager.ensure(structTree, "serializable");
+    try {
+      const structTree = await this.pdfManager.ensure(
+        this,
+        "_parseStructTree",
+        [structTreeRoot]
+      );
+      const data = await this.pdfManager.ensure(structTree, "serializable");
+      return data;
+    } catch (ex) {
+      warn(`getStructTree: "${ex}".`);
+      return null;
+    }
   }
 
   /**

From bf553f22da96a6e61dfa9b5804af273a6b13852d Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Thu, 17 Apr 2025 14:01:53 +0200
Subject: [PATCH 2/2] Ensure that the /P-entry is actually a dictionary in
 `StructTreePage.prototype.addNode`

This may fix issue 19822, but without a test-case it's simply impossible to know for sure.
---
 src/core/struct_tree.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/core/struct_tree.js b/src/core/struct_tree.js
index a8766e92e..59ba40cb6 100644
--- a/src/core/struct_tree.js
+++ b/src/core/struct_tree.js
@@ -757,7 +757,10 @@ class StructTreePage {
 
     const parent = dict.get("P");
 
-    if (!parent || isName(parent.get("Type"), "StructTreeRoot")) {
+    if (
+      !(parent instanceof Dict) ||
+      isName(parent.get("Type"), "StructTreeRoot")
+    ) {
       if (!this.addTopLevelNode(dict, element)) {
         map.delete(dict);
       }