From b78ce5ffd3f5751dc6f8a10b69385973798e6020 Mon Sep 17 00:00:00 2001
From: konstantin-s <konstantin-s@konstantin-s>
Date: Thu, 28 Jan 2021 17:21:46 +0500
Subject: [PATCH 1/3] Added support mbstring.func_overload=2

Probably resolves issue https://github.com/dompdf/dompdf/issues/2298
---
 src/FontLib/Glyph/Outline.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/FontLib/Glyph/Outline.php b/src/FontLib/Glyph/Outline.php
index 330db09..f2b15d3 100644
--- a/src/FontLib/Glyph/Outline.php
+++ b/src/FontLib/Glyph/Outline.php
@@ -96,7 +96,7 @@ function parseData() {
   function encode() {
     $font = $this->getFont();
 
-    return $font->write($this->raw, strlen($this->raw));
+    return $font->write($this->raw, mb_strlen($this->raw, '8bit'));
   }
 
   function getSVGContours() {

From 4281c76eed812732696836a765a4f7516111cbf2 Mon Sep 17 00:00:00 2001
From: Brian Sweeney <brian@eclecticgeek.com>
Date: Sat, 11 Dec 2021 17:15:43 -0500
Subject: [PATCH 2/3] Use MBString functions for 8bit data read

Prevents issues with MBString overrides of standard PHP functions.
---
 src/FontLib/EOT/File.php             | 3 +--
 src/FontLib/Table/DirectoryEntry.php | 4 ++--
 src/FontLib/TrueType/File.php        | 2 +-
 src/FontLib/WOFF/File.php            | 2 +-
 4 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/FontLib/EOT/File.php b/src/FontLib/EOT/File.php
index 13d5925..cd3fff6 100644
--- a/src/FontLib/EOT/File.php
+++ b/src/FontLib/EOT/File.php
@@ -74,8 +74,7 @@ public function read($n) {
     }
 
     $string = fread($this->f, $n);
-    $chunks = str_split($string, 2);
-    $chunks = array_map("strrev", $chunks);
+    $chunks = mb_str_split($string, 2, '8bit');
 
     return implode("", $chunks);
   }
diff --git a/src/FontLib/Table/DirectoryEntry.php b/src/FontLib/Table/DirectoryEntry.php
index 2b5846d..6a1c52a 100644
--- a/src/FontLib/Table/DirectoryEntry.php
+++ b/src/FontLib/Table/DirectoryEntry.php
@@ -37,14 +37,14 @@ class DirectoryEntry extends BinaryStream {
   protected $origF;
 
   static function computeChecksum($data) {
-    $len = strlen($data);
+    $len = mb_strlen($data, '8bit');
     $mod = $len % 4;
 
     if ($mod) {
       $data = str_pad($data, $len + (4 - $mod), "\0");
     }
 
-    $len = strlen($data);
+    $len = mb_strlen($data, '8bit');
 
     $hi = 0x0000;
     $lo = 0x0000;
diff --git a/src/FontLib/TrueType/File.php b/src/FontLib/TrueType/File.php
index b61da0f..3594479 100644
--- a/src/FontLib/TrueType/File.php
+++ b/src/FontLib/TrueType/File.php
@@ -124,7 +124,7 @@ function parse() {
   }
 
   function utf8toUnicode($str) {
-    $len = strlen($str);
+    $len = mb_strlen($str, '8bit');
     $out = array();
 
     for ($i = 0; $i < $len; $i++) {
diff --git a/src/FontLib/WOFF/File.php b/src/FontLib/WOFF/File.php
index 9e54b3f..9056e94 100644
--- a/src/FontLib/WOFF/File.php
+++ b/src/FontLib/WOFF/File.php
@@ -50,7 +50,7 @@ public function load($file) {
       }
 
       // Prepare data ...
-      $length        = strlen($data);
+      $length        = mb_strlen($data, '8bit');
       $entry->length = $entry->origLength = $length;
       $entry->offset = $dataOffset;
 

From 5cce9d9a60e6a5d12d2e634b2fe54c07582e0621 Mon Sep 17 00:00:00 2001
From: Brian Sweeney <brian@eclecticgeek.com>
Date: Sat, 11 Dec 2021 17:22:10 -0500
Subject: [PATCH 3/3] Require MBString PHP extension

---
 composer.json | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/composer.json b/composer.json
index 6176f19..29b0653 100644
--- a/composer.json
+++ b/composer.json
@@ -23,6 +23,9 @@
     "config": {
         "bin-dir": "bin"
     },
+    "require": {
+        "ext-mbstring": "*"
+    },
     "require-dev": {
         "symfony/phpunit-bridge" : "^3 || ^4 || ^5"
     }