From 83f7009e4b013c1d671f18ee565720f9e0a36b00 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 21 Apr 2021 12:14:33 +0200
Subject: [PATCH] Change `NameOrNumberTree.getAll` to return a `Map` rather
 than an Object

Given that we're (almost) always iterating through the result of the `getAll`-calls, using a `Map` seems nicer overall since it's more suited to iteration compared to a regular Object.

Also, add a couple of `Dict`-checks in existing code touched by this patch, since it really cannot hurt to prevent *potential* errors in a corrupt PDF document.
---
 src/core/catalog.js          | 29 +++++++++++++----------------
 src/core/name_number_tree.js | 15 ++++++++-------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/src/core/catalog.js b/src/core/catalog.js
index 47df1ab36..1b3d7e154 100644
--- a/src/core/catalog.js
+++ b/src/core/catalog.js
@@ -514,9 +514,8 @@ class Catalog {
     const obj = this._readDests(),
       dests = Object.create(null);
     if (obj instanceof NameTree) {
-      const names = obj.getAll();
-      for (const name in names) {
-        dests[name] = fetchDestination(names[name]);
+      for (const [key, value] of obj.getAll()) {
+        dests[key] = fetchDestination(value);
       }
     } else if (obj instanceof Dict) {
       obj.forEach(function (key, value) {
@@ -582,8 +581,9 @@ class Catalog {
       currentIndex = 1;
 
     for (let i = 0, ii = this.numPages; i < ii; i++) {
-      if (i in nums) {
-        const labelDict = nums[i];
+      const labelDict = nums.get(i);
+
+      if (labelDict !== undefined) {
         if (!isDict(labelDict)) {
           throw new FormatError("PageLabel is not a dictionary.");
         }
@@ -879,15 +879,14 @@ class Catalog {
     const obj = this._catDict.get("Names");
     let attachments = null;
 
-    if (obj && obj.has("EmbeddedFiles")) {
+    if (obj instanceof Dict && obj.has("EmbeddedFiles")) {
       const nameTree = new NameTree(obj.getRaw("EmbeddedFiles"), this.xref);
-      const names = nameTree.getAll();
-      for (const name in names) {
-        const fs = new FileSpec(names[name], this.xref);
+      for (const [key, value] of nameTree.getAll()) {
+        const fs = new FileSpec(value, this.xref);
         if (!attachments) {
           attachments = Object.create(null);
         }
-        attachments[stringToPDFString(name)] = fs.serializable;
+        attachments[stringToPDFString(key)] = fs.serializable;
       }
     }
     return shadow(this, "attachments", attachments);
@@ -916,15 +915,13 @@ class Catalog {
       javaScript.set(name, stringToPDFString(js));
     }
 
-    if (obj && obj.has("JavaScript")) {
+    if (obj instanceof Dict && obj.has("JavaScript")) {
       const nameTree = new NameTree(obj.getRaw("JavaScript"), this.xref);
-      const names = nameTree.getAll();
-      for (const name in names) {
+      for (const [key, value] of nameTree.getAll()) {
         // We don't use most JavaScript in PDF documents. This code is
         // defensive so we don't cause errors on document load.
-        const jsDict = names[name];
-        if (isDict(jsDict)) {
-          appendIfJavaScriptDict(name, jsDict);
+        if (value instanceof Dict) {
+          appendIfJavaScriptDict(key, value);
         }
       }
     }
diff --git a/src/core/name_number_tree.js b/src/core/name_number_tree.js
index 19b90bf51..588cad7f9 100644
--- a/src/core/name_number_tree.js
+++ b/src/core/name_number_tree.js
@@ -32,9 +32,9 @@ class NameOrNumberTree {
   }
 
   getAll() {
-    const dict = Object.create(null);
+    const map = new Map();
     if (!this.root) {
-      return dict;
+      return map;
     }
     const xref = this.xref;
     // Reading Name/Number tree.
@@ -59,13 +59,14 @@ class NameOrNumberTree {
         continue;
       }
       const entries = obj.get(this._type);
-      if (Array.isArray(entries)) {
-        for (let i = 0, ii = entries.length; i < ii; i += 2) {
-          dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
-        }
+      if (!Array.isArray(entries)) {
+        continue;
+      }
+      for (let i = 0, ii = entries.length; i < ii; i += 2) {
+        map.set(xref.fetchIfRef(entries[i]), xref.fetchIfRef(entries[i + 1]));
       }
     }
-    return dict;
+    return map;
   }
 
   get(key) {