From 1bf711fe1fcc8d9a7d1f067c06e1fe356cf05bc3 Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Tue, 19 Apr 2016 15:43:59 +0100
Subject: [PATCH] Guard against mbstring func_overload, fixes #5218

---
 src/Composer/Downloader/GzipDownloader.php |  2 +-
 src/Composer/Util/Platform.php             | 18 ++++++++++++++++++
 src/Composer/Util/RemoteFilesystem.php     |  2 +-
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/Composer/Downloader/GzipDownloader.php b/src/Composer/Downloader/GzipDownloader.php
index 9969578e5..19e4a45e1 100644
--- a/src/Composer/Downloader/GzipDownloader.php
+++ b/src/Composer/Downloader/GzipDownloader.php
@@ -76,7 +76,7 @@ class GzipDownloader extends ArchiveDownloader
         $archiveFile = gzopen($file, 'rb');
         $targetFile = fopen($targetFilepath, 'wb');
         while ($string = gzread($archiveFile, 4096)) {
-            fwrite($targetFile, $string, strlen($string));
+            fwrite($targetFile, $string, Platform::strlen($string));
         }
         gzclose($archiveFile);
         fclose($targetFile);
diff --git a/src/Composer/Util/Platform.php b/src/Composer/Util/Platform.php
index 8939b9467..252041d66 100644
--- a/src/Composer/Util/Platform.php
+++ b/src/Composer/Util/Platform.php
@@ -26,4 +26,22 @@ class Platform
     {
         return defined('PHP_WINDOWS_VERSION_BUILD');
     }
+
+    /**
+     * @param  string $str
+     * @return int return a guaranteed binary length of the string, regardless of silly mbstring configs
+     */
+    public static function strlen($str)
+    {
+        static $useMbString = null;
+        if (null === $useMbString) {
+            $useMbString = function_exists('mb_strlen') && ini_get('mbstring.func_overload');
+        }
+
+        if ($useMbString) {
+            return mb_strlen($str, '8bit');
+        }
+
+        return strlen($str);
+    }
 }
diff --git a/src/Composer/Util/RemoteFilesystem.php b/src/Composer/Util/RemoteFilesystem.php
index 56d2a2e68..bbdcc3851 100644
--- a/src/Composer/Util/RemoteFilesystem.php
+++ b/src/Composer/Util/RemoteFilesystem.php
@@ -277,7 +277,7 @@ class RemoteFilesystem
         try {
             $result = file_get_contents($fileUrl, false, $ctx);
 
-            if ($this->bytesMax && strlen($result) < $this->bytesMax) {
+            if ($this->bytesMax && Platform::strlen($result) < $this->bytesMax) {
                 // alas, this is not possible via the stream callback because STREAM_NOTIFY_COMPLETED is documented, but not implemented anywhere in PHP
                 throw new TransportException('Content-Length mismatch');
             }