Fix handling flex://defaults

Author: nicolas-grekas

src/Downloader.php

@@ -29,8 +29,8 @@
 class Downloader
 {
     private const DEFAULT_ENDPOINTS = [
-        'https://api.github.com/repos/symfony/recipes/contents/index.json?ref=flex/main' => [],
-        'https://api.github.com/repos/symfony/recipes-contrib/contents/index.json?ref=flex/main' => [],
+        'https://api.github.com/repos/symfony/recipes/contents/index.json?ref=flex/main',
+        'https://api.github.com/repos/symfony/recipes-contrib/contents/index.json?ref=flex/main',
     ];
     private const MAX_LENGTH = 1000;
 
@@ -63,25 +63,29 @@ public function __construct(Composer $composer, IoInterface $io, $rfs)
                 $this->endpoints = null;
                 $this->legacyEndpoint = 'https://flex.symfony.com';
             }
-        } elseif (\is_array($endpoint) || false !== strpos($endpoint, '.json')) {
-            $this->endpoints = array_fill_keys((array) $endpoint, []);
+        } elseif (\is_array($endpoint) || false !== strpos($endpoint, '.json') || 'flex://defaults' === $endpoint) {
+            $this->endpoints = array_values((array) $endpoint);
         } else {
             $this->legacyEndpoint = rtrim($endpoint, '/');
         }
 
         if (false === $endpoint = getenv('SYMFONY_ENDPOINT')) {
             // no-op
-        } elseif (false !== strpos($endpoint, '.json')) {
+        } elseif (false !== strpos($endpoint, '.json') || 'flex://defaults' === $endpoint) {
             $this->endpoints ?? $this->endpoints = self::DEFAULT_ENDPOINTS;
-            $this->endpoints = [$endpoint => []] + $this->endpoints;
+            array_unshift($this->endpoints, $endpoint);
             $this->legacyEndpoint = null;
         } else {
             $this->endpoints = null;
             $this->legacyEndpoint = rtrim($endpoint, '/');
         }
 
-        if (null !== $this->endpoints && false !== $i = array_search('flex://defaults', $this->endpoints, true)) {
-            array_splice($this->endpoints, $i, 1, self::DEFAULT_ENDPOINTS);
+        if (null !== $this->endpoints) {
+            if (false !== $i = array_search('flex://defaults', $this->endpoints, true)) {
+                array_splice($this->endpoints, $i, 1, self::DEFAULT_ENDPOINTS);
+            }
+
+            $this->endpoints = array_fill_keys($this->endpoints, []);
         }
 
         $this->io = $io;