From 60bd9580e2e24910fc526388615db5ee9c8a4c45 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Wed, 13 Jul 2022 10:06:16 +0200
Subject: [PATCH] Ignore invalid /CIDToGIDMap-entries when parsing fonts (issue
 15139)

In the referenced PDF document the fonts have /CIDToGIDMap-entries that cannot be loaded. Hence, only when `ignoreErrors` is set, we'll now ignore these corrupt /CIDToGIDMap-entries and fallback to simply assume that no such data is available.

Given that this is *clearly* a case of a corrupt PDF document, there's no guarantee that this will "fix" things in the general case since a /CIDToGIDMap may be *required* in order for some composite fonts to render correctly. However, attempting to render *something* is surely better than skipping a font altogether.
---
 src/core/evaluator.js         | 13 ++++++++++---
 test/pdfs/issue15139.pdf.link |  1 +
 test/test_manifest.json       |  8 ++++++++
 3 files changed, 19 insertions(+), 3 deletions(-)
 create mode 100644 test/pdfs/issue15139.pdf.link

diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 213e9b4c1..9684ff218 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -3373,9 +3373,16 @@ class PartialEvaluator {
         };
       }
 
-      const cidToGidMap = dict.get("CIDToGIDMap");
-      if (cidToGidMap instanceof BaseStream) {
-        cidToGidBytes = cidToGidMap.getBytes();
+      try {
+        const cidToGidMap = dict.get("CIDToGIDMap");
+        if (cidToGidMap instanceof BaseStream) {
+          cidToGidBytes = cidToGidMap.getBytes();
+        }
+      } catch (ex) {
+        if (!this.options.ignoreErrors) {
+          throw ex;
+        }
+        warn(`extractDataStructures - ignoring CIDToGIDMap data: "${ex}".`);
       }
     }
 
diff --git a/test/pdfs/issue15139.pdf.link b/test/pdfs/issue15139.pdf.link
new file mode 100644
index 000000000..2402f5053
--- /dev/null
+++ b/test/pdfs/issue15139.pdf.link
@@ -0,0 +1 @@
+https://github.com/mozilla/pdf.js/files/9137443/sample4a.pdf
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 703da1161..1f19ce771 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -4980,6 +4980,14 @@
        "lastPage": 1,
        "type": "eq"
     },
+    {  "id": "issue15139",
+       "file": "pdfs/issue15139.pdf",
+       "md5": "0f2beb6a788d1e47bb9af737f6670493",
+       "rounds": 1,
+       "link": true,
+       "lastPage": 1,
+       "type": "eq"
+    },
     {  "id": "gesamt",
       "file": "pdfs/gesamt.pdf",
       "md5": "743aaa6f46ed0a42864f079d632d942e",