Fix phpversion() returning false when an extension has no version, fixes #10631

src/Composer/Platform/Runtime.php

@@ -98,7 +98,12 @@ class Runtime
      */
     public function getExtensionVersion(string $extension): string
     {
-        return phpversion($extension);
+        $version = phpversion($extension);
+        if ($version === false) {
+            $version = '0';
+        }
+
+        return $version;
     }
 
     /**

src/Composer/Repository/PlatformRepository.php

@@ -618,13 +618,8 @@ class PlatformRepository extends ArrayRepository
 
     /**
      * Parses the version and adds a new package to the repository
-     *
-     * @param string      $name
-     * @param null|string $prettyVersion
-     *
-     * @return void
      */
-    private function addExtension(string $name, ?string $prettyVersion): void
+    private function addExtension(string $name, string $prettyVersion): void
     {
         $extraDescription = null;