From 947d390421b61dedfcb79c209d49e43af0d05dbd Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Mon, 5 Sep 2022 11:56:02 +0200
Subject: [PATCH] Fallback to a standard font when a Type1 font program is
 empty (issue 15292)

*Please note:* This is only a, hopefully generally helpful, work-around rather than a proper solution to issue 15292.

There's something that's "special" about the Type1 fonts in the referenced PDF document, since we don't manage to find any actual font programs and thus cannot render anything.
Given that it shouldn't make sense for a Type1 font program to ever be empty, since that means that there's no glyph-data to render, we simply fallback to a standard font to at least try and render *something* in these rare cases.
---
 src/core/type1_font.js        | 5 ++++-
 test/pdfs/issue15292.pdf.link | 1 +
 test/test_manifest.json       | 8 ++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 test/pdfs/issue15292.pdf.link

diff --git a/src/core/type1_font.js b/src/core/type1_font.js
index 3ff2240c58133..10ff3aeb86830 100644
--- a/src/core/type1_font.js
+++ b/src/core/type1_font.js
@@ -24,11 +24,11 @@ import {
   CFFStrings,
   CFFTopDict,
 } from "./cff_parser.js";
+import { FormatError, warn } from "../shared/util.js";
 import { SEAC_ANALYSIS_ENABLED, type1FontGlyphMapping } from "./fonts_utils.js";
 import { isWhiteSpace } from "./core_utils.js";
 import { Stream } from "./stream.js";
 import { Type1Parser } from "./type1_parser.js";
-import { warn } from "../shared/util.js";
 
 function findBlock(streamBytes, signature, startIndex) {
   const streamBytesLength = streamBytes.length;
@@ -140,6 +140,9 @@ function getEexecBlock(stream, suggestedLength) {
   // in the returned eexec block. In practice this does *not* seem to matter,
   // since `Type1Parser_extractFontProgram` will skip over any non-commands.
   const eexecBytes = stream.getBytes();
+  if (eexecBytes.length === 0) {
+    throw new FormatError("getEexecBlock - no font program found.");
+  }
   return {
     stream: new Stream(eexecBytes),
     length: eexecBytes.length,
diff --git a/test/pdfs/issue15292.pdf.link b/test/pdfs/issue15292.pdf.link
new file mode 100644
index 0000000000000..b4401058f5279
--- /dev/null
+++ b/test/pdfs/issue15292.pdf.link
@@ -0,0 +1 @@
+https://github.com/mozilla/pdf.js/files/9288663/issue15292.pdf
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 186bfae2a3ab3..f577e88a73a95 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -153,6 +153,14 @@
        "lastPage": 1,
        "type": "eq"
     },
+    {  "id": "issue15292",
+       "file": "pdfs/issue15292.pdf",
+       "md5": "24297e183bf16cdd684dac8902e9fbe6",
+       "rounds": 1,
+       "link": true,
+       "lastPage": 1,
+       "type": "eq"
+    },
     {  "id": "issue11549",
        "file": "pdfs/issue11549_reduced.pdf",
        "md5": "a1ea636f413e02e10dbdf379ab4a99ae",