From 2ae5aa08cc37fadcb65cefc11b6286e50ababc8c Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Fri, 27 Dec 2024 11:41:49 +0100
Subject: [PATCH] Assert that the `fontMatrix` is always valid in
 `compileGlyph`

While [bug 1893645](https://bugzilla.mozilla.org/show_bug.cgi?id=1893645) was fixed some time ago now, it still shouldn't hurt to also assert that the `fontMatrix` is always valid when invoking the `compileGlyph` method.
---
 src/core/font_renderer.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/font_renderer.js b/src/core/font_renderer.js
index 37342fc300dc9..b076e35b7b860 100644
--- a/src/core/font_renderer.js
+++ b/src/core/font_renderer.js
@@ -14,6 +14,7 @@
  */
 
 import {
+  assert,
   bytesToString,
   FONT_IDENTITY_MATRIX,
   FormatError,
@@ -23,6 +24,7 @@ import {
 } from "../shared/util.js";
 import { CFFParser } from "./cff_parser.js";
 import { getGlyphsUnicode } from "./glyphlist.js";
+import { isNumberArray } from "./core_utils.js";
 import { StandardEncoding } from "./encodings.js";
 import { Stream } from "./stream.js";
 
@@ -834,6 +836,7 @@ class CompiledFont {
         warn("Invalid fd index for glyph index.");
       }
     }
+    assert(isNumberArray(fontMatrix, 6), "Expected a valid fontMatrix.");
 
     const cmds = new Commands();
     cmds.transform(fontMatrix.slice());