Fix for PearRepository scheme handling, broke ChannelReaderTest.

src/Composer/Repository/PearRepository.php

@@ -107,7 +107,7 @@ class PearRepository extends ArrayRepository
                 // distribution url must be read from /r/{packageName}/{version}.xml::/r/g:text()
                 // but this location is 'de-facto' standard
                 $urlBits = parse_url($this->url);
-                $scheme = ('https' === $urlBits['scheme'] && extension_loaded('openssl')) ? 'https' : 'http';
+                $scheme = (isset($urlBits['scheme']) && 'https' === $urlBits['scheme'] && extension_loaded('openssl')) ? 'https' : 'http';
                 $distUrl = "{$scheme}://{$packageDefinition->getChannelName()}/get/{$packageDefinition->getPackageName()}-{$version}.tgz";
 
                 $requires = array();