@seldaek damn your assignment in expression

src/Composer/Repository/ComposerRepository.php

@@ -585,7 +585,7 @@ class ComposerRepository extends ArrayRepository
         }
 
         // url-encode $ signs in URLs as bad proxies choke on them
-        if ($pos = strpos($filename, '$') && preg_match('{^https?://.*}i', $filename)) {
+        if (($pos = strpos($filename, '$')) && preg_match('{^https?://.*}i', $filename)) {
             $filename = substr($filename, 0, $pos) . '%24' . substr($filename, $pos+1);
         }