From c3d40ae79a3c0bc00e2aceba1571019bb9ce3257 Mon Sep 17 00:00:00 2001
From: Jordi Boggiano <j.boggiano@seld.be>
Date: Fri, 17 Jul 2020 17:16:19 +0200
Subject: [PATCH] Fix passing of repo http options in async requests

---
 src/Composer/Repository/ComposerRepository.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Composer/Repository/ComposerRepository.php b/src/Composer/Repository/ComposerRepository.php
index 941cf08dd..78c6cf495 100644
--- a/src/Composer/Repository/ComposerRepository.php
+++ b/src/Composer/Repository/ComposerRepository.php
@@ -1202,7 +1202,13 @@ class ComposerRepository extends ArrayRepository implements ConfigurableReposito
             $filename = $preFileDownloadEvent->getProcessedUrl();
         }
 
-        $options = $lastModifiedTime ? array('http' => array('header' => array('If-Modified-Since: '.$lastModifiedTime))) : array();
+        $options = $this->options;
+        if ($lastModifiedTime) {
+            if (isset($options['http']['header'])) {
+                $options['http']['header'] = (array) $options['http']['header'];
+            }
+            $options['http']['header'][] = array('If-Modified-Since: '.$lastModifiedTime);
+        }
 
         $io = $this->io;
         $url = $this->url;